Index
Page numbers printed in bold face indicate the location in the book where the term is defined, or where theprimary discussion of it is located.
* (host), 177, 178, 180, 181, 184, 185*. ATT. COM (host), 31.. (directory), 65, 69, 86... (file), 305, 306.NET, see Microsoft, .NET
.gift (file), 123.htaccess (file), 85.pdf (file), 79.rhosts (file), 44, 56, 59, 60, 156, 168.s.c (program), 306.shosts (file), 156.ssh (directory), 105.ssh/authorized keys2 (file), 156.ssh/id dsa (file), 156.ssh/id dsa.pub (file), 156$HOME/.rhosts (file), 60/usr/lib/term/.s (directory), 426/bin (directory), 290, 293/bin/sh (file), 166/ches/index.html (file), 78/dev (directory), 295/dev/kmem (file), 43/dev/tty (file), 163, 293/etc (directory), 268/etc/group (file), 163, 268/etc/hosts (file), 295/etc/hosts.equiv (file), 59, 60/etc/inetd.conf (file), 122, 165, 266, 267,
269
/etc/motd (file), 268, 294, 303, 309/etc/passwd (file), 50, 56, 57, 60, 96, 98,
163, 168, 268/etc/resolv.conf (file), 163, 201/home/rubin/www-etc/.htpw1(directory), 85/lib (directory), 163/lib/rld (file), 163/private/32-frobozz#$ (file), 57/usr/apache (directory), 165/usr/ftp (directory), 60/usr/lib (directory), 163, 305, 309/usr/lib (file), 305/usr/lib// (directory), 305/usr/lib/lbb.aa (file), 309/usr/lib/libc.so.1 (file), 163/usr/lib/libm.so (file), 163/usr/lib/sendmail (file), 168, 302, 310/usr/lib/term/.s (directory), 298/usr/local/boot (directory), 52/usr/spool/uucppublic (directory), 60/usr/var/tmp (directory), 305, 306/var/spool/mqueue (directory), 43
1.2.3.4 (host), 189, 190
10.11.12.13 (host), 190
127.0.0.1 (host), 71
192.20.225.4 (host), 32
2600 Magazine, 349
4.225.20.192. IN - ADDR . ARPA (host), 32
5.6.7.8 (host), 189, 190
5.7.6.8 (host), 189
6over4 (program), 37
6to4 (program), 37
7 ESS . MYMEGACORP. COM (host), 33
802.11, 38, 105, 242

397
Licensed under a Creative Commons Attribution-Non-CommericialNoDerivatives 4.0 International (CC BY-NC-ND 4.0) license
https://creativecommons.org/licenses/by-nc-nd/4.0/

Index

398
WEP, see WEP

A1 (host), 320
A2 (host), 320
access control lists, 48
ACM (Association for Computing Machinery),
353
ActiveX, 264
filtering with a proxy, 202
uses digital signatures, 270
Web browser controls for, 84
Address Resolution Protocol, see ARP
address-based authentication, see authentication,
address-based
address-spoofing, see attacks, address-spoofing
adjunct password file, see passwords, file,
shadow
Adleman, Leonard, 343
administration, 296
Administrator (account), 123, 210
ADMINNET (host), 184
Adobe
Acrobat Reader, 79
adrian (account), 288, 289
Advanced Encryption Standard, see AES
Advanced Research Projects Agency, see
DARPAadware, 69
AES (Advanced Encryption Standard), 40,
337–339
modes of operation, 338
AFS (Andrew File System), 52
authentication, 52
AH (Authentication Header), 36, 318, 319
AIM, see AOL, Instant Messenger
Airsnort (program), 39
AIX
setuid programs on, 124
Alderson drive, 233
alligators, 65
Allman, Eric, 158
AllowUsers, 156
America Online, see AOL
Andrew File System, see AFS
ANI, 260
anonymous (account), 55

anonymous certificates, see certificates,
anonymousanonymous FTP, see FTP, anonymous
AntiSniff, 159
anycast addresses, 35
AOL
Instant Messenger
U NIX client, 46
connects to master servers, 45
passwords sniffed by dsniff, 129
AP news, 309
Apache Web server, 270
jailing, 165–167
on medium-security hosts, 255
restricting file access, 85
shared libraries and, 165
suexec and, 167
version 2.0, 165
APOP, see POP3, APOP authentication
applets, 81
arms races, xiii
snort and attack packets, 283
between virus writers and detection
software, 107, 331
cryptographic key length, 338
for acquiring root, 125
password pickers vs. password guessers, 95
spoofers vs. packet telescope sizes andlocations, 117
spotting DOS attack packets, 111
ARMY. COM (host), 78
ARP (Address Resolution Protocol), 22
replaced by ND in IPv6, 36
spoofing, 22, 34, 160
man-in-the-middle attacks, 118
ARPA, 19
ARPANET, 19
AS (Autonomous System), 30
path, 31ASCII
7-bit in SMTP, 41
in FTP transfers, 55
routine use for safe messages, 205
used by SIP, 47
ASN.1, 62
security problems with, 62
used by H.323, 47

Index399
used by LDAP, 65
used in MIBs, 62
Association for Computing Machinery, see ACM
assurance requirements, 12, 102astronauts, 67
asymmetric cryptosystems, see cryptography,
public key
asymmetric routing, see routing, asymmetric
Asynchronous Transfer Mode, see ATM
AT&T Corp., 99, 248
divestiture, 11
net 12.0.0.0/8, 116
phone book, 97
AT&T Labs
VPN, 244
ATM (Asynchronous Transfer Mode), 20, 182
ATT. ORG (host), 78
attachments, 205
attacks, 95–118
active, 59, 117–118, 337
address scanning, 33
address-spoofing, 23, 27, 48, 104, 149, 161,
179, 183
ARP-spoofing, 22, 34, 118
back doors, 100–103
in shared libraries, 164birthday, 337, 346
bogus NIS backup servers, 50change file timestamps, 63chosen-plaintext, 336
code book, 339
connection laundering, 8
cryptographic, 313, 336
cut-and-paste, 337
denial-of-service, see DOS
dictionary, 50, 53, 60, 62, 96, 287
hacking tools for, 129
on POP3/APOP, 204
distributed denial-of-service, see DDoS
DNS cache contamination, 32
DNS spoofing, 330
DNS zone transfers, 31
dumpster diving, 132
executable files in FTP area, 65
exhaustive search, 336, 338
exponential, 106–107
fetching /etc/passwd, 98

FMS, 39
forged signatures, 327
hiding, 126–127
inside, 14, 186, 187
IP fragmentation, 21
IP source routing, 29, 179
IP spoofing, 72
Kerberos authenticators, 317
known-plaintext, 336
laundering connections, 299
mail address-spoofing, 99
man-in-the-middle, 337, 344
DHCP subject to, 34
MBone packets through a packet filter, 67
name server, 149
name-spoofing, 32, 59
network scans, 33
on Kerberos’ initial ticket, 317
on smart cards, 147
oracle, 337
passive eavesdropping, 29, 128, 337
password logging, 128
power attacks, 147
practical cryptanalysis, 336
protocol holes, 104race, 144
replay, 149, 314, 326, 337
during clock skew, 144
foiled by different challenge, 148
IVs prevent, 340
Kerberos authenticators, 317
on Web servers, 76
set back time, 64
routing, 28, 29
rubber hose, 336
Smurf, 110
directed broadcasts and, 71
use directed broadcasts, 121
sniffing, xiii, 310
social engineering, 132
subversion by route confusion, 183
subverting routing with ICMP Redirect,
27
SYN flood, xiii
SYN packets, 109
TCP hijacking, xiii
TCP sequence number, 23, 29, 104, 118

Index400
temporary visitor account, 99
through guest account, 12
time-spoofing, 63–64, 337
timing attacks, 147traffic analysis, 318
Trojan horse, 52, 57, 58, 63, 100, 128
using CGI scripts, 166
using PATH, 123version-rollback, 45
via trusted hosts, 60
weak random number generation
NFS, 51
weakest link, 102
auditing
concealing from, 63
nmap has limited value for, 130
Orange Book and, 11
sensitive hosts, 8
with netstat, 267
authentication, 137–151
address–based
ssh and, 158
address-based, 23, 32, 60, 70, 149
fails, 28
based on internal and external DNS, 198
based on source address, 149
bidirectional, 315
BSD, 59
by name, 51, 59
challenge/response, 145–147, 317, 342, 346
X11, 71
cryptographic, 64, 103, 137, 149–150, 313
database, 138, 144
failures, 103–104
for proxy use, 188
handheld authenticators, 138
host-to-host, 149–150
Kerberos, 11, 313–317
in AFS, 52
Lamport’s algorithm, 146–147
magic cookie, 71
name-based, 32, 149
network-based, 149
NFS, 51, 52
not provided by UDP, 27
one-factor
in ssh, 154–156

one-time passwords
races, 104
OSPF, 29
other, 137
passwords
machine-chosen, 139
user-chosen, 138
philosophy, 99–100
pki, 150–151
Radius, 148
RPC, 48
SASL, 149
server, 146
SNMP, 326
something you are, 137
something you have, 137, 146
something you know, 137, 138, 146
tickets, 316
time-based, 64, 144, 342
tokens, 260
two-factor, 137
in ssh, 157
upper management, 138
X11, 103
Authentication Header, see AH
authentication races, 104authenticator, 314, 316
handheld, 14, 59, 105, 144, 146, 149
authorization, 48, 137
authorized keys (file), 105
automatic teller machine, 146
Autonomous System, see AS
awk (program), 219

B (host), 320
b (account), 290, 291
B1 (host), 320
B2 (host), 320
back doors, 11, 100–103
backscatter, 116–117
backupday-zero, 270, 273
DNS servers, 31
encrypting tapes, 16
network links, 183
NIS servers, 50

Index401
of safe hosts, 273
bansho, 4
Basic Authentication, 85
basket, 279
battlements, 11beferdd (account), 291
Beijing, perimeter failure near, 5
Bell Laboratories
Plan 9 project, see Plan 9
XUNET project, 301
BELL - LABS (host), 78
BELLDASHLABS (host), 78
Bellovin
Daniel, 2
Rebecca, 2Sam, 2
Steve, 287, 295
Sylvia, 2
belt-and-suspenders, 4, 255
Berferd, 125, 287–299
mother of, 299
origin of, 298–299
berferd (account), 78, 291, 295
Berkeley packet filter, see BPF
BGP (Border Gateway Protocol), 30–31
diverting packet flows with, 30
filtering announcements, 30
filtering out bad packets with, 113, 115
MD5 authentication, 30
problems with fixing, 30
under increasing attack, 331
bibtex (program), 355
big nose, 167
big words
Alyce, 139
anathema, 11bansho, 4chimera, 9concomitant, 102
cyclotrimethylenetrinitramine, 207
demimonde, 56
deprecated, 120, 287
ecchymosis, 139
helminthiasis, 206
immortelle, 139
indicia, 280
metastasis, 127

monoculture, 112
monostely, 139neologism, 192, 288
obviate, 183
pedagogy, 197
postern, 11
provenance, xvii, 103
sanguine, 12
tautological, 85bin (account), 60, 125, 297
bin (directory), 60, 123, 166
bindgraph patch rates, 276
bind (account), 170bind (program), 31, 275, 276
bind, 43
biometrics, 147–148, 260
birds
African swallow, 239
European swallow, 239
pigeon, 235
birds of a feather, see BoF
birthday paradox, 347
bitrot, 312
black box testing, 230
black-bag jobs, 8
black-holed, 249
blaster, atom, 119
Bloom filter, 113
BoF (birds of a feather), 353
boofhead, 53
BOOTP, 33–34
Border Gateway Protocol, see BGP
Borisov, Nikita, 38
botnets, 117bots, 117
bounce attacks, ftp, 55
BPF (Berkeley packet filter), 214
branch offices
VPNs and, 237
BrickHouse (program), 220
bro (program), 214, 282
broadcast
DHCP, 33
relayed elsewhere, 34
directed, 71
disable forwarding of, 21

Index402
scanning for hosts with, 121
DOS using the small services, 71
format of, 21
in IPv6, 36
monitoring at a firewall, 219
multicast and, 36
storms, 72
TFTP router configuration with, 53
X11 XDMCP messages, 71
brute force, see attacks, exhaustive search
BSD, 255
authentication, 59
often defaults to all services turned off, 255
ps command, 292
uses client pull, 274
BSD/OS
setuid programs on, 124
BSDI, 261
BSD/OS, 72
buffer overruns, see stack-smashingbugs, 100–103
in critical systems, 16
in ftpd, 56
in MIME processing, 43
in WWW file pointers, 65
old ones aren’t fixed, 13
possible, in router, 9
programs are assumed to have, 5, 11
source routing, 183
Bugtraq, 82, 83, 122, 350
bugtraq (account), 416
bulkheads, 253byte code, 81

C, 86
C (host), 320
C++, 81
CA (Certificate Authority), 150
SSL and root, 325
X.509 uses, 326
cache, 316, 317
caller ID, 260
CAST, 327
CBC (Cipher Block Chaining), 339, 340
CCS (Computers and Communication Security),
353

CD-ROM, 299
CERT (Computer Emergency Response Team),xiii, 184, 292, 309, 311, 350
Advisories, 350
CA-00:11, 108
CA-1992-11, 164
CA-1992:15, 6
CA-1995-03a, 15
CA-1997-22, 170
CA-1997-27, 55
CA-1998-05, 170, 275
CA-1998-07, 15
CA-1999-14, 170
CA-1999-15, 15, 61
CA-2000-02, 83
CA-2001-02, 170
CA-2001-04, 80
CA-2001-09, 24
CA-2001-26, 83
CA-2002-03, 62
CA-2002-06, 148
CA-2002-18, 275
CA-2002-23, 15
CA-2002-24, 275
CA-2002-27, 15, 117, 171
CA-91:04, 99
CA-95.01, 24
CA-95:13, 158
CA-96.03, 262
CA-96.06, 167
CA-96.21, 24
CA-96:26, 108
CA-97.24, 167
CA-97.28, 21
Incident Notes
IN-2000-02, 58
Vendor-Initiated Bulletins
VB-95:08, 71
Vulnerability Notes
VN-98.06, 83
VU#32650 - DOS, 58
VU#40327, 61
VU#596827, 61
VU#846832, 164
Certificate Authority, see CA
certificates, 345
PGP, 327

Index403
Web access, 77
CFB (Cipher Feedback), 341
CGI (Common Gateway Interface), 77
CGI scripts, 86, 87, 166
chroot and, 165, 167
creating with anonymous FTP access, 65
easier to write than X11 programs, 91
hacking targets, 167
more dangerous than Java, 80
need wrappers, 86
replaced with Java applets, 82
shell escape characters and, 86
CGI wrappers, 86, 166–167
CGIWrap (program), 165, 167
challenge/response, see authentication,
challenge/response
Chapin, A. Lyman, 28
Chapman, Brent, 177, 199, 201, 232
chargen (program), 71
chargen, 72
checksumIP, see IP, checksum
Kerberos message, 314
MAC, 345
ches (account), 129
Cheswick
Kestrel, 2
Lorette Ellane Petersen Archer, xx, 2Richard R., 2
Ruth, 2
Terry, 2
William, 287
chfn (program), 126
childrenare like employees, 241
Chinese Lottery, 117
chmod, 56
chpass (program), 126
chroot, 162–167
anonymous FTP and, 167
Apache Web server and, 165
application-level filters, 210
building a honeypot with, 295
CGI scripts, 167
chrootuid and, 163
core dumps and, 162
denial-of-service from, 162difficult to set up, 163
for CGI scripts, 165
IMAP and, 168
inetd calls, 154limitations, 162–163
named and, 170
POP3 and, 168
root can break out of, 162
SMTP daemon and, 168
ssh UsePrivilegeSeparation and, 158
suggested modification to, 166
support files in, 166
system call requires root privileges, 163
to a separate partition, 162
Web servers and, 66, 87
chroot (program), 163
chsh (program), 126
chutzpah, 99
CIDR (Classless Inter-Domain Routing), 21
defines an intranet, 252
ipchains, 219
CIFS (Common Internet File System), 58
CIO, 247
Cipher Block Chaining, see CBC
Cipher Feedback, see CFB
Cipher Newsletter, 350
ciphersuites, 83
ciphertext, 335
circuit gateways, see gateways, circuit level
Cisco Netflow, 114
Cisco routers
IP DEBUG, 114
patch information, 352
use configuration files, 214
Citrix ICA
passwords sniffed by dsniff, 129
CLARK (host), 310–312
CLARK . RESEARCH . ATT. COM (host), 301
Classless Inter-Domain Routing, see CIDR
click-through license agreements, 275
client programs, 23
client pull, 274
client shim, 175, 243
clock, 64, 315
clock skew limits, 317
clog (program), 275
CNN, 290, 295

Index404
Code Red worm, see worms, Code Red
COM (host), 78
COM . COM . COM (host), 78
COM . EDU (host), 32
COMDOTCOM . COM (host), 78
Comer, Doug, 19
command node, 110
Commercial Off-The-Shelf, see COTS
Common Gateway Interface, see CGICommon Internet File System, see CIFS
common-mode failure, 67, 180
Computer Emergency Response Team, see
CERTComputers and Communication Security, see
CCSconf (directory), 166
configuration
disk space, 268
message-of-the-day, 268
routing, 268
configure (program), 165
connection filtering, 188
consoleaccess, 271–272
administration through, 267
local access only, 272
logins only allowed through, 264
RS-232 switch, 272
servers, 272
software switch, 272
cookies, 75–76, 79
browsers configured to reject, 76
hackers put scripts in, 79
JavaScript can steal authentication datafrom, 82
recommendations about, 84
warnings in Netscape, 79
COPS (program), 126, 268, 302
copyright law, 56
corporate, 9
COTS (Commercial Off-The-Shelf), 153
counter mode, 338
counterintelligence, 17CPU, 147
crack, see hacking tools, crack
CREEP, 105
creeping featurism

in inetd, 267
cribs, 336
cron (program), 60
cross-site scripting
slash, 82
cryptanalysis, 8, 15, 313
differential, 338
cryptographic protocols, 335
cryptography, 11, 15–16, 63, 64, 313–328,
335–347, see also encryption
asymmetric, see cryptography, public key
block cipher, 339
cipher block chaining mode, 339–340
cipher feedback mode, 341
client keys, 316
conventional, 337, 342
counter mode, 341
digital signature, see digital signatureselectronic code book mode, 339
encryption, see encryption
exponential key exchange, 343–344
not authenticated, 344
initialization vector, 339–340
key, 335
key distribution systems, 343
legal restrictions, 314, 346
master keys, 314, 336, 342
modes of operation, 337, 339–341
multi-session keys, 314
output feedback mode, 340
padding, 340
private key, 337–342
encrypted with passwords, 50
proprietary, 335
protocols, 313
timestamps in, 63
public key, 150, 326, 342–343
disadvantages, 343
S-BGP, 30
secret key, see cryptography, private key
secure hash functions, 346–347
session keys, 314, 315, 317, 336, 342–344
symmetric, see cryptography, private key
timestamps, 347
on a document, 347
cryptosystemsecret-key, 337

Index405
cryptosystems, 313
csh, 293
cvs
managing firewall rules with, 232
passwords sniffed by dsniff, 129
ssh and, 238
C preprocessor, 221

D’Angelo, Diana, 287, 296
D1 (host), 320
D2 (host), 320
daemon (account), 166
dangerous programs
wu-ftpd, 167
DARPA, 19
DASS, 328
Data Encryption Standard, see DES
database
authentication
troubles with, 144–145
datagram, 20, 27, see also UDP
day-zero
backup, 270, 273
daytime (program), 71
DCE (Distributed Computing Environment), 48
dd (program), 273
DDoS (Distributed Denial-of-Service), 107,
109–117
attack tools, 131trinoo, 131
botnets and, 117
can only be mitigated, 107
diagram of, 110
flooding network links with, 108
hard to traceback, 107
mitigation, 111
Debian Linux, 261
DEC, 211, see Digital Equipment Corporation
Decision, 290–295
DECnet, xviii
decryption, see cryptography
DECstation 5000, 302
defense in depth, 4, 9, 15, 310
filtering e-mail, 206
demilitarized zone, see DMZ
demise, 15

denial-of-service, see DOS
DenyUsers, 156
DES (Data Encryption Standard), 327, 337–338
CBC mode, 326
modes of operation, 338
secure RPC uses, 48
used to secure SNMP, 326
dessert topping, see floor wax
destination unreachable, see ICMP, messages,
Destination Unreachable
device driver, 19
dhclient (program), 34
DHCP (Dynamic Host Configuration Protocol),33–34, 38
comparison with DHCPv6, 36
firewall rules and, 219
relay, 34
war driving and, 242
DHCPv6, 36
dial-up access, 256
diceware, 142–143
Dick Van Dyke Show, 291
dictionary attacks, 96
Diffie-Hellman, 48, 343
dig, 162
dig (program), 160, 162
Digital Equipments, 78
digital rights management, see DRM, 331
Digital Signature Standard, see DSS
digital signatures, 344–345
of secure hashes, 346
of software packages, 270
digital timestamp, 347
link value, 347
linking, 347
Dijkstra, Edsger W., 5
DILBERT. COM (host), 90
directed broadcast, 121
directed broadcasts, 21
disable forwarding of, 21
directories..., 127
X11 font library, 52
dirty words, 186, 204
discard (program), 71
discrete logarithm, 344
diskless workstations, 52Index406
Distance Vector Multicast Routing Protocol, see
DVMRP
Distributed Computing Environment, see DCE
Distributed Denial-of-Service, see DDoS
DMZ (demilitarized zone), 14–15, 89, 160, 179
provisioning hosts on, 156
semi-secure software in, 255
used to interface between companies, 237,
249
Web servers should be in, 87
DNS (Domain Name System), 31–33, 72
alias for FTP server, 199
allowed between departments, 257
backup servers, 31
block zone transfers, 184cache contamination, 32
commands
forwarder, 201cross-checks, 32, 59, 201
dangerous misfeature, 32
dig queries, 160
external service, 199
filtering, 198–201, 224
gateway’s resolution, 201
internal access, 199
internal root, 199
internal service, 199
internal service of external names, 199–201
inverse queries, 32, 33
controlling, 32
lookup sequence, 32
permit UDP queries, 184
proposed KX record, 241
records
A, 31, 201
AAAA, 31
CNAME, 31
DNSKEY, 31
HINFO, 31, 32
MX, 31, 32
NAPTR, 31
NS, 31
PTR, 31, 32, 201
SIG, 31, 33, 34
SOA, 31, 160
SRV, 31
WKS, 31rich source of target information, 32, 106
secondary servers, 33
sequence number vulnerability, 104
table of record types, 31
tree structure, 31
tunnels and, 239
used to tunnel, 235
wildcard records, 32
zone example, 199
zone transfers, 31, 33
DNS proxy, 198
DNSsec, 33
needed for the KX record, 241
needed with VPNs, 239
predictions about, 330
spoofing tools widespread, 330
domain and type enforcement, see DTE
Domain Name System, see DNS
dongle, see authenticator, handheld
doorbell, 249
Dorward, Sean, 310
DOS (denial-of-service), 42, 71, 107–116, 159,
265, 266, 268
DHCP subject to, 34
exhausting disk space, 109
from chroot environments, 162
ICMP, 108, 209
IP source address spoofing, 107remove rpcbind service, 48
syslogd and, 159
Web servers and, 167
downstream liability, 311
DRM (digital rights management), 275
DS1, 185
dselect (program), 270
dsniff, see hacking tools, dsniff
dsniff (program), 76, 123, 129
DSO (dynamic shared object), 165
DSS (Digital Signature Standard), 345
DTE (domain and type enforcement), 163
DUAL Gatekeeper, 215
dump (program), 273
dumpster, 5
diving, 132
Dutch law, 297, 298
DVMRP (Distance Vector Multicast Routing
Protocol), 67

Index407
Dynamic Host Configuration Protocol, see
DHCP
dynamic packet filter, see packet filters, dynamic
dynamic shared object, see DSO

E (host), 320
e-mail, see maileavesdropping, 8
on phone connections, 256
eBay, 82, 332
ECB (Electronic Code Book), 339
echo (program), 71, 72, 164
eEye Digital Security, 119
efficiency, 103
eggs, 279
egress filtering, 177
asymmetric routes and, 115
Eindhoven University, 297
Einstein, Albert, 5Electronic Code Book, see ECB
electronic emissions, 8electronic mail, see mailelvish, see fonts, Tengwar
email, see e-mail
EMBEZZLE . STANFORD . EDU (host), 288, 290
Encapsulating Security Protocol, see ESP
encapsulation, 67, 233, 234
encryption, 59, 234, 236, see also cryptography
AES, see AES
application level, 322–328
block cipher, 338
end-to-end, 242
preferred over link-layer encryption,
40
file, 8first block, 339
key-id, 318
last block, 339
link level, 318
mail, 326–327
network level, 318–322
SNMP, 326
stream cipher, 339
to authentication servers, 144
transport level, 319
triple, 342

English Channel, 16
ensniff.c (program), 128
entrapment, 17
environment variables$PATH, 52
TERM, 127
erotica, 56
error propagation, 340, 341
es.c (file), 305, 306
ESMTP, 41
ESP (Encapsulating Security Protocol), 318
espionage, see industrial espionage
ESPN . COM (host), 90
Esser, Thomas, 435
etc (directory), 166
ethereal (program), 160, 282
Ethernet, 21–22
ARP and, 22
broadcasts ARP requests, 22
cut transmit wire to, 295
in hotels, 242
in the home, 239
monitoring packets on, 29, 182monitoring with tcpdump, 295
private connections over, 262
rpcbind designed for, 50
ethics, 16–17
of counter infections, 56
scanning tools, 128–129
ettercap (program), 158
exec (program), 127
expiration
key, 345
expire (program), 66
exponential key exchange, 48, see cryptography,
exponential key exchange
exponentiation, 343
External Data Representation, see XDR
extranets, 247

F (host), 320
factoring, 343
factors, 137
Family Educational Rights and Privacy Act, see
FERPA
FAQ (frequently asked questions), 128

Index408
Farmer, Dan
in a hot tub, 241
on finger, 64
scanned Web server hosts, 129
FEP (Firewall Enhancement Protocol), 228
FERPA (Family Educational Rights and PrivacyAct), 106
FG . NET (host), 42
field, 344
field (account), 96
file handle, see NFS, file handle
file systems
Andrew, 52
NFS, 51–52
prevent filling, 102
remote, 317
simulated, see jail partition
wiped out by hackers, 294
File Transfer Protocol, see FTP
files
hidden, 127
filtering, 197–210, see also packet filtering
application level, 185–186, 226–227
circuit level, 186–188
DOS packets, 111–114
e-mail, 206–207
FTP, 202
GRE tunnels, 209
guidelines, 210
H.323, 208
ICMP messages, 209–210
IP over IP, 209
IPsec, 209
NTP, 203
POP and IMAP, 204
RealAudio, 208
SIP, 208
SMB, 209
SMTP, 203–204
ssh, 206
TCP sessions, 202–203
UDP, 207–208
Web, 202
X11, 209
filtering bridge, 160
filtering languages
ipchains, 216–220

ipfw, 220
ipf, 220–226
find (program), 308
FingerDiane, 2Finger (program), 64
finger, 64
gets hole in, 100
provides cracking information, 105provides hacking information, 42
finger (program), 64, 65, 98, 100, 105, 293, 301
fingerprint, 147
fingerprinting, see hosts, fingerprinting
Finisar, 160
fink (program), 270
Firewalk (program), 230
firewalking, 121, 229–230
avoided by IP-blocking gateways, 211
avoided with relays, 186
ipchains allows, 217
with ICMP Path MTU messages, 209
firewalking (program), 229
firewallproblems, 227–230
Firewall Enhancement Protocol, see FEP
firewall rules, 212–214
code walk-through, 232
inspecting, 232
samples, 216–226“temporary”, 228, 232
testing, 220
firewalls, 11, 13, 175–195, see also gateways
administration, 230
application-based, 226–227
as bulkheads, 253
building, 215–227
bypassing with tunnels, 235
categories, 175
corporate, 257
departmental, 257–258
distributed, 193–194
engineering, 211–232
for an organization, 220–226
FTP and, 229
history of, 211
implementation options, 188–190
ineffective on large perimeters, 253

Index409
limitations of, 194–195
placement, 257–258
point, 258
positioning, 253–255
regression testing, 231
replicated, 191–193
rules and DHCP, 219
rulesets, 212–214
simple, 216–220
testing, 230–232
using NAT, 38
Web servers and, 89–90
Firewalls mailing list, 199, 350
first edition, xiii
FLEEBLE . COM (host), 199
floor wax, see dessert topping
FMS attack, 39
foistware, 69, 241
fonts
Hebrew Hclassic, 329
Tengwar, 95
FOO .7 ESS . MYMEGACORP. COM (host), 33
FOO . COM (host), 32
FOO . COM . BIG . EDU (host), 32
FOO . COM . CS . BIG . EDU (host), 32
FOO . COM . EDU (host), 32
FOO . FLEEBLE . COM (host), 199
forensics, 272, 303–311
DHCP logs, 34
needs accurate time stamps, 63
Radius logs, 34
using file access times, 308–309
forgery, see spoofing
forward, 200
fragmentation, see packet filtering,fragmentation
fragrouter (program), 231, 280
frame relay, 182
France, 289
FreeBSD, 165, 220, 261, 264, 270
field stripping, 266
ports collection, 270, 274
setuid programs on, 124
frequently asked questions, see FAQ
frobozz (program), 210
fsirand (program), 51
ftp (account), 168

ftp (program), xiii, 4, 59, 138, 228
FTP (File Transfer Protocol), 53–57, 65, see also
ftpd
anonymous, 55–57, 65, 167–168
configuring, 168
attacks on, 60
bogus passwd file, 57, 98, 288, 290
bounce attacks, 55
configuring, 57, 65, 109, 268
control channel, 53
data connection
over SSL on port 989, 171
denial-of-service with, 109
directory
publicly writable, 56
filtering, 202
firewalls and, 228
incoming, 57
over SSL on port 990, 171
passive, 103, 188
Web browsers, 77
passive data channel, 53–55
passive is preferred, 55
passwords sniffed by dsniff, 129
processing in firewalls, 229
sample session, 54
spoken by Web browsers, 74transfer modes, 55
tunneling with, 235
Web browsers and, 77
ftp PORT (program), 228
ftpd
commands
PASV, 53, 55, 188
PORT, 53, 188
TYPE I, 55
PASS, 103
USER, 103
configuring, 167–168
DNS cross-checking, 201
logging, 96
modifications, 167–168
privileges needed, 103
selecting version, 167
ftpd (program), 167
FTPS, 171
FTPS-data, 171

Index410
garlicsmb likes, 287
Gartner Group, 87
gas mask, 290
gatewaysapplication level, 175, 199, 255
belt-and-suspenders, 255
circuit level, 175, 186–188, 199, 255, 280,
see also tunnelingdepends on correct router configuration, 9
fail-safe design, 9
has professional administration, 13
leaks, 236
mail, 186
packet filtering, 175
paranoid, 255
relay services, 187
FTP, 199
mail, 180, 199
netnews, 66
services, see services
simple administration, 12
topology, 180, 181
gcc (program), 261
GECOS, 126
Generic Security Service Application Program
Interface, see GSS-API
gethostbyaddr, 32
gets (program), 155gets, 100
Ghengis Kahn, 5Glick, Paul, 287, 296
Global Positioning System, see GPS
glue routines, 47
gnu keyring (program), 142
Goldberg, Ian, 38
Google, 128, 351
GPS (Global Positioning System), 63
Grampp, Fred, 262
graphical user interface, see GUI
GRE tunnels, 30
filtering, 209
Great Wall of China, 5grep (program), 187, 219
Groove Networks, 235
Gross, Andrew, 123, 308
group (file), 166

GSS-API (Generic Security Service Application
Program Interface), 48, 327, 328
NFS servers, 51
guest (account), 12, 96, 295
GUI (graphical user interface), 213
discussion, 213
in ethereal, 160
Guninski, Georgi, 83
GW (host), 179, 180, 200

H.323, 46–47
filtering, 188, 208
proxy, 215
Haber, S, 347
Hacker Off-the-Shelf, see HOTS
hackers, xix
are out to get you, 102
attacking Stanford, 289
attacks, see attacks
attacks stimulates tool production, 289
Dutch, 298
go after log files first, 159
goals, 8
legally untouchable, 299
malicious, 8, 159, 294
managing, 287
monitor Ethernets, 59
remove logs first, 60
tools, 119–133
availability, 119
network monitoring, 295
wipe file systems, 294
would you hire, 132
hackerz
doodz, 127
lamerz, 128sploits, 122
warez, see warez
hacking
attacks often launched on holidays, 308
goals, 121, 301
recovery from, 127, 303
hacking tools, 128–131
crack, 129
dsniff, 129–130
nuke.c, 27

Index411
ethics, 128–129
hunt, 118
IP-Watcher, 118
Juggernaut, 118
juggernaut, 130
l0phtcrack, 129
nbaudit, 58, 130
nessus, 131
nmap, 130
Ping of Death, 131trinoo, 131
Virus construction kits, 131
handheld authenticator, see authenticator,
handheld
Hanlon’s Razor, 227
Hansen, Stephen, 289, 296
hash2.0, see snefru
headhunters, 105
helper applications, 79
hidden filenames, 127with leading period, 123
hijacking, see also TCP, hijacking
Web, 84
Hoffman, J., see fonts, Hebrew Hclassic
Hoffman, Joel, 435
home directory, 60
FTP writable, 56of system accounts, 60
home networks, 239
employers often pay for, 239
home LAN security is hard, 241
linked to corporate intranets, 241–242
running SMB on, 169
honeyd (program), 130, 282
Honeyman, Peter, 275
honeypots, 281
for Berferd, 295–298
misleading nmap, 130with chroot, 295
H OST A (host), 183
host leaks, 236, 252detecting, 236
H OST Z (host), 183
host-based security, 253–255, 258
HostbasedAuthentication, 154
hostsback doors into, 127

breaking into, 122–126
covering tracks, 126–127
fingerprinting, 122, 130with ICMP Time Exceeded, 252
multi-homed, 23
obtaining root on, 123–127
hosts (file), 199
hosts.equiv (file), 154
Hotmail, 83, 203, 227
HOTS (Hacker Off-the-Shelf), 22
HP printer driverscanned a network, 282
HPUX
setuid programs on, 124HTML (Hypertext Markup Language), 74
forms, 76
generated by JavaScript, 82
hidden fields in raw, 77
in attachments, 205
in e-mail to bypass JavaScript checks, 83
in HTTP responses, 75
inserted in user responses, 82
is easier than X11, 91
HTTP (Hypertext Transfer Protocol), 65, 74–77
authentication sniffed by dsniff, 76
cookies, see cookies
DELETE command, 76
GET command, 74, 76
LOCATION command, 75
maintaining connection state, 76–77
over SSL on port 443, 171
POST command, 76
PUT command, 76
query description, 74
REDIRECT command, 75
sample session, 74
server responses, 75
sessions, 76–77
httpd (program), 166
httpd.conf (file), 165, 166
HTTPS, 171
httpsfor administrative access, 184
implemented with sslwrap, 171
Httptunnel (program), 228
Hushmail, 203
Hussein, Saddam, 288

Index412
Hypertext Markup Language, see HTML
Hypertext Transfer Protocol, see HTTP

ı, 201
IBM, 338
research, 168
Thinkpad, 332
ICMP (Internet Control Message Protocol),27–28
can change routing, 27
denial-of-service with bogus packets, 108
Destination Unreachable, 28
DOS attacks, 108, 209
distinguishing “safe” and “unsafe” packets,
209
Echo Reply, 217
Echo Request
traceroute and, 160
filtering, 209–210
for v6, 28
Fragmentation Needed, 217
Need Fragment, 217
Path MTU Discovery, 27–28
don’t block, 209
firewalking with, 209
Port Invalid
traceroute, 209
Redirectmodify route tables with, 27
reports routing problems, 27
Time Exceeded, 217
traceroute and, 160, 209
ICMPv6, 28
icons (directory), 166
ICQ
connects to master servers, 46
passwords sniffed by dsniff, 129
id dsa.pub (file), 156
IDEA, 327
ident (program), 217
identification, 137
Identification Friend or Foe, see IFF
IDS (intrusion detection system), xv, 279
administering, 282
limitations of, 279–280
placement of, 280–281

Shadow, 159
tools, 282–283
types, 281–282
IE, see MSIEIEEE 802.11, see 802.11
IEFBR14.DLL (program), 226
IETF (Internet Engineering Task Force), 67
IFF (Identification Friend or Foe), 145
IGMP, 67
IKE (Internet Key Exchange), 318, 320
IKEv2, 322
IM (Instant Messaging), 45
IMAP, 45
filtering, 204
on medium-security hosts, 255
over SSL on port 993, 171
safe implementation of, 168–169
stack-smashing attack detected by snort,
283
imap (program), 149
IMAPS, 171
in.telnetd (file), 306
incoming
access policy, 184
access to port 2049, 52
calls, abuse, 187
FTP directory, 56
mail, 31, 177, 199
proxy use, 188routing messages, 181ssh, 199
I N DNS (host), 200
industrial espionage, 32, 42
inetd
back door in, 127
discussion, 153–154
TCP wrappers and, 154
inetd (program), 43, 71, 87, 153, 154, 165, 169,
170, 267
inetd.conf (file), 267, 292
information leakage, 105–106
information security, 8
information theory, 97
ingress filtering, 177
init (program), 127, 216
initialization vector, see IV
input, 219

Index413
INSIDE - NET (host), 185
insiders
rejecting a firewall, 236
installation, see configuration
Instant Messaging, see IM
instant messaging, 45–46
AOL, 45
ICQ, 46
IRC, 46
jabber, 46
Microsoft Messenger, 46
SSL and, 46
integrity checking, 15
internal users, see insiders
Internetin the home, 331
mapping, 248
shutdown incoming access, 184
Internet Control Message Protocol, see ICMPInternet Engineering Task Force, see IETF
Internet Group Management Protocol, 67Internet Key Exchange, see IKE
Internet Liberation Front, 302
Internet Printing Protocol, see IPP
Internet Protocol, see IP
Internet Relay Chat, see IRC
Internet security
predictions about, 331–332
we are losing ground, 332
Internet service provider, see ISP
Internet Society, see ISOC
Internet telephony, 46–47
Internet Worm, 43, 100
Interop, xiii
intranet, 14, 60
intranets, 247–258
address allocation efficiency, 252
fax lines used to compromise, 248
host leaks, 252
leaksrouting, 248
mapping, 248–249
mergers and divestitures modify, 248
open routers on, 252routing, 249
statistics, 252
unknown connections into, 247

intrusion detection, 279–282
snort, 282–283
port scans, 121
intrusion detection system, see IDS
IP (Internet Protocol), 19, 20–21
broadcast, 67, see also broadcast
checksum, 20
delivery isn’t guaranteed, 20
filtering fragments, 228
fragmentation, 21
header, 19–21, 319
hops, 21
host address, 21IP-transparent gateways
may force IP renumbering, 249
NAT and, 249
launderingwith circuit gateways, 187
multicast, 67
group, 67
network address, 21
options, 29, 179
filtering, 29
packets, 20
protocol 41 (6to4), 37
routing, see routing
source addresses are trustable, 20
source routing, 29, 179, 183, 255
loose, 29
spoofing, xiii, 20
backscatter from, 116
sequence numbers for, 72
tools available, 71
telephony, 46–47
TTL field
can limit Mbone distribution, 68
crude host fingerprinting with, 252
default values from SNMP queries, 62
finding distance to a firewall with, 230
gives clues to attacker’s distance, 114
low values in a DOS attack, 113
small values can fool an IDS, 280
traceroute uses, 160
tunneling, 234, 319
with DNS, 235
tunneling IPv6 packets, 36–37
unicast, 67

Index414
use of bogus addresses internally, 183
IP addresses
allocating, 249
intentional misuse of, 249
IP over IP, 235
filtering, 209
IP Security Policy, see IPSP
Ipchains, 220
Ipchains (program), 216, 220
ipchains, see filtering languages, ipchains
ipchains (program), 214–216, 219, 220
ipchains -L (program), 218
ipchains-restore (program), 218
ipchains-save (program), 218
ipchains-save input (program), 218
Ipf (program), 226
ipf, see filtering languages, ipf
can filter tunneled IPv6 traffic, 37
ipf (program), 37, 214, 215, 220, 221
ipf.conf (file), 221
ipf.conf.restrictive (file), 221
ipftest, 226
ipftest (program), 226
ipf, see filtering languages, ipfw
ipfw (program), 214, 216, 220
iplog (program), 130
IPP (Internet Printing Protocol), 235, 264
IPsec, 118, 242, 271, 318–322
AH, 318–319
broken by Windows reconfiguration, 243configuring is hard, 243
ESP, 318–319
filtering, 209graph of possible configurations, 321
interactions with NAT, 242
key management, 320–322
keys compromised by malware, 243
NAT and, 38
placement, 319–320
Windows applications and, 243
IPSP (IP Security Policy), 320
Iptables (program), 216
IPv4, see also IP
address format, 21
multicast, 67
IPv6, 34–37, 126
address formats, 35–36

anycast addresses, 35
DHCPv6, 36
economic drivers?, 330
Filtering, 36–37
hardware acceleration in routers, 329
link-local addresses, 36
multicast, 36
ND, 36
network numbers may change frequently,
35
predictions about, 329–330
site-local addresses, 35
supported on U NIX-like platforms, 329
tunneling through IPv4, 36–37
Iraq, 288
irc (program), 219
IRC (Internet Relay Chat), 117, 349
passwords sniffed by dsniff, 129
used to control botnets, 117
IRC (program), 46
Irix 6.2, 166
ISDN, 46
ISOC (Internet Society), 353
ISP (Internet service provider), 58, 114
ISS, 131
IV (initialization vector), 39, 326, 339, 340

jabber (program), 46
jail, see chroot
jail (program), 163, 165, 167
jail partition, 295–299
Java, 80–82, 264, 277
native methods, 81–82
resistant to buffer overflows, 210
Web browser controls for, 84Java Web Server, 82
JavaScript, 82–83, 264, 277
bypassing deactivation of, 83
cross-site scripting, 82
Web browser controls for, 84
Jeeves, 82
Jerusalem, 290
juggernaut, see hacking tools, juggernaut

k5su (program), 126

Index415
KDC (Key Distribution Center), 150, 314, 336
external, 316
must be available in real time, 342
safeguarding, 15
keep it simple, stupid, see KISS
Kerberized Internet Negotiation of Keys, see
KINK
Kerberos, 11, 150, 314–317, 328
attacks on initial ticket, 317
authentication, 313
authenticators, 317
connecting outside realm, 316
in ssh, 157
in Windows 2000, 313
instance, 314
key distribution, 314
limitations of, 316–317
no handheld authenticators for, 317
primary name, 314
principal, 314, 315
realm, 314
ticket, 314
ticket-granting ticket, 317
variant of X11, 71
Kerberos V4bugs in, 262
kernelconfiguration, see configuration, kernel
keycache, 316
database, 50, 146, 147
distribution, 15, 314, 320, 327
Kerberos, 314
distribution problems, 71
escrow, 15
expiration, 345
exponential exchange, 48
lifetime, 318
session, 48
stealing, 336
Key Distribution Center, see KDC
keyinfo (program), 126
keyinit (program), 126
keyrings, 327
killer packets, 108
KINK (Kerberized Internet Negotiation ofKeys), 320

KISS (keep it simple, stupid), 212
known-hosts (file), 323
KoblasDavid, 187
Michelle, 187
Kolstad, Rob, 108

L0pht
AntiSniff, 159
L0phtcrack, 129
L2TP (Layer Two Tunneling Protocol), 235
Lamport, Leslie, 146
LANmisconfigured router on the gateway, 182
network encryption on, 320
LanManager, see Windows NT, LanManager
laptop, 156
Large Installation Systems Administration, see
LISA
lastlog (file), 127
LATEX, 270, 435
Laugh-in, 42
laundering connections, see attacks, connection
laundering
law enforcement, xix
notifying when attacked, 311
Layer Two Tunneling Protocol, see L2TP
lbb.aa (file), 309
ldap (program), 149
LDAP (Lightweight Directory Access Protocol),65
PGP keys distributed with, 327
leaks
host, 236, 252routing, 182, 236, 251
least privilege, 5, 102, 212
Leech, Marcus, 117lex (program), 102
lib.msg (file), 309
lib/codepages (directory), 169
lib/etc/smbpasswd (file), 169
libpcap (program), 282
library, see also shared libraries
get host names, 32
X11 font, 52
libtool (program), 165

Index416
Lightweight Directory Access Protocol, see
LDAPLimoncelli, Tom, xvi, 87
link levelencryption, 318
link-local address, 36Linux, xviii, 163, 220, 264, 270
Debian, 261
field stripping, 266
for a cheap firewall box, 257
in hardware VPN product, 244
increasing target for viruses, 106
often defaults to all services turned off, 255
personal firewall for, 215, 216–220
Red Hat, 261
have public key in ROM BIOS?, 332
RPMS and, 270
secure, 163
setuid programs on, 124
Slackware, 261
Slapper worm and, 111
ipchains, 214
supports IPv6, 329
uses client pull, 274
lip-print, 147
LISA (Large Installation Systems
Administration), 353
load average, 43
lock (program), 126
lockpicking, 120
locks
automobile, 6
hotel doors, 6
locks (directory), 169
log (directory), 166
logged-in, 219
logged-out, 219
logging, 8, 158–159, 272–273
drop safe, 159, 272
needs disk space, 268
off-machine, 159
synchronized with timestamps, 63
TCP destination, 187with rpcinfo command, 48
login (program), xvii, 58, 95, 96, 127, 164, 295,
297
logs, see also logging

altering, 126
logs (directory), 166
Los Alamos, 289
loss of life, 16
Love bug worm, 243
lpq (program), 126
lpr (program), 126
lprm (program), 126ls (program), 52, 57, 99, 123, 304, 305
Lumeta Corp., 248, 252lures, see honeypots

m4, 221
MAC (message authentication code), 315, 340,
347
Mac OS/X
uses client pull, 274
Macintosh
Rendezvous service, 264
configuration, 264
OS/X.2, 264
virus target, 106
magic cookie, 71
mail, 41–45, 179
aliases on gateway, 42aliases provide hacking clues, 42application gateway, 186
bombing, 108
cryptographic, 100delivery, 180delivery through a packet filter, 178
expertise at gateway, 42filtering policy discussion, 203–204
gateway, 186
headers, 42
incoming, 177
mailing list, 42
multimedia, see MIME
return address not reliable, 42
mail (program), 201
MAILGATE (host), 185
mailing list
firewalls, 350
bugtraq, 350
vuln-dev, 350
VulnDiscuss, 350

Index

417
VulnWatch, 350
man, 129
managed code, 263
management information base, see MIB
manzier, 282
mapping
intranets, 248–249
the Internet, 248
Markoff, John, 298
masquerading, 216
MBone, 67–68
ports, 67
MD5, 327, 347
mDNS protocol, 264
media, xix
Meeting Maker
passwords sniffed by dsniff, 129
Melissa worm, 106, 205, 243, 253
message authentication code, see MAC
MIB (management information base), 62
micro httpd (program), 87
Microsoft.NET, 263–264
risks, 264
ActiveX, 80, see ActiveX
CIFS proposed by, 58
DOS commands, 123
IIS, 87
Internet Explorer, see MSIE
Messenger, 46
NetMeeting, 46
Office, 205
Outlook Express, 44
PPTP authentication, 129
reserves right to change software on a host,275
RPC and, 47
security initiative, 330–331
signs ActiveX with digital signatures, 270
SMB protocol used by, 57
SMS, 193
source code unavailable, 114
SQL passwords sniffed by dsniff, 129
uses client pull, 274
will support IPv6, 329
Windows, see Windows
Windows Media Player, 274

Word, 205
examining files in U NIX, 205
Word macros, 131
Wordpad, 213
Microsoft Internet Explorer, see MSIE
Middle East, 293
military, 9milk, adulterated, 120
MIME (Multipurpose Internet Mail Extensions),
43–44, 65
uses PostScript, 44
mime.types (file), 166
mind, boggled, 16
minimal trust, 43
MIT, 113, 314
MLS (multilevel secure system), 10
moat, 204
mobile hosts, 234
modes of operation, see cryptographic, modes ofoperation
Mogul, Jeff, xx, 229
monitoring, 58–60, 290, 295–296, 326
tools, 289
wiretap, 8, 96
monoculture, 89, 106, 112
monsters
cookie, 75
moat, 204
Morris Worm, see worms, Morris
Morris, Bob, 59, 98, 100
Morris, Robert (not junior), 23–24
mrinfo (program), 126
MS-DOS, xviii
MSIE (Microsoft Internet Explorer), see also
Web browsers, 83
ActiveX and, 80
defaults to FTP PORT command, 55
S/MIME in, 326
mtrace (program), 126
MTU discovery
permitted in filter, 217
Muffett, Alec, 129
multi-homed host, 23
multicast, 68, see IP, multicast
backbone, see MBonerouters, 67
session directory, 67Index418
multilevel secure system, see MLS
Multipurpose Internet Mail Extensions, seeMIME
Muus, Mike, 131
MYBANK . COM (host), 78

NAI Sniffer
passwords sniffed by dsniff, 129
naim (program), 46
name service, see also DNS
attacks on, 149
dumping the database, 162
external, 201
internal, 201
namedsafe implementation of, 170
named (program), 170
NANOG (The North American Network
Operators’ Group), 110
Napsterpasswords sniffed by dsniff, 129
NAS (Network Access Server), 148
NASA, 67
Nass, Simona, 242
nat (program), 130
NAT (Network Address Translation), 37–38
as a firewall, 38
in hotel networks, 242
incompatible with some kinds ofencryption, 38
interactions with IPsec, 242
private address space and, 37
National Bureau of Standards, 338
National Security Agency, see NSA, 338
native methods, 81
nbaudit, see hacking tools, nbaudit
nbaudit (program), 58
NBC Dateline, 309
NBS, see National Bureau of Standards
NCR
setuid programs on, 124
ND (Neighbor Discovery), 36
NDSS (Networks and Distributed Systems
Security), 353
Neighbor Discovery, see ND
Neighbor Solicitation, 36

nessus, see hacking tools, nessus
nessus (program), 351
NET (host), 78
N ET 1 (host), 180, 182, 183
N ET 100 (host), 183
N ET 2 (host), 179, 180, 182
N ET 3 (host), 179, 180, 182
NetBIOS, 169
block with departmental firewalls, 257
netbios (program), 214
NetBSD, 164, 261, 270
field stripping, 266
setuid programs on, 124
Netherlands, 297
NetInfo (program), 264
NetMeeting, 237
uses UDP packets, 215
netnews, 66
on a gateway, 66
processing on the gateway, 66
resource hog, 66
security holes in, 66
NetOptics, 160
Netscape, see also Web browsers
can display cookie warnings, 79
S/MIME in, 326
uses client pull, 274
netstat (program), 267, 295, 303
netstat -a (program), 226
netware, xviii
network
backup links, 183
elements, 265
configuring with GUIs, 213
control with SNMP, 326
default passwords not changed in, 265
frequent reconfiguration of, 265
monitoring, 271
ROM updates, 274
SNMP management of, 62
Web configuration of, 91
layersdiagram of, 20
scanners, 121–122
locating hosts with, 121
scanning
by HP printer driver, 282

Index419
standard management tools, 236
topology, 183
Network Access Server, see NAS
Network Address Translation, see NAT
Network File System, see NFS
Network Flight Recorder, see NFR
Network IDS, see NIDS
Network Information Service, see NIS
Network News Transfer Protocol, see NNTP
Network Time Protocol, see NTP
Networks and Distributed Systems Security, see
NDSS
New York Times, 43, 298, 347
Newsday, 309
newsgroupscomp.risks, 350
proprietary, 66
NFR (Network Flight Recorder), 214
NFS (Network File System), 51–52, 264
blocked from outside at a university, 184disable setuid programs over, 52
file handle, 51
stale, 51
is (mostly) stateless, 51
passwords sniffed by dsniff, 129
port numbers, 51–52
root access prohibited, 51
root file handle, 51
ssh and, 105
suspicious access to, 208
Version 3, 52
nice (program), 162
NIDS (Network IDS), 279
Nimda worm, 83, 87
NIS (Network Information Service), 50, 98
NIST, see National Bureau of Standards, 345,
347
nmap, 130
nmap (program), 130, 131, 226, 282
nmapNT (program), 119nntp (program), 66
NNTP (Network News Transfer Protocol),
66–67
spoken by Web browsers, 74
nntpd (program), 66, 67
nobody (account), 169
nohup (program), 309

nohup.out (file), 309
Northcutt, Stephen, 159
NOYFB, 84
NSA (National Security Agency), 5, 100, 338
NSF
block with departmental firewalls, 257
nslookup (program), 160
NTBugtraq, 350
ntp (program), 63, 126
NTP (Network Time Protocol), 63–64
filtering, 203, 225
on medium-security hosts, 255
permit access, 184
relatively safe UDP protocol, 208
NTP. INSIDE (host), 184, 185
NTP. OUTSIDE (host), 184, 185
ntpdate (program), 126
nuke.c (program), 128

od (program), 305
OFB (output feedback), 340, 341
one-factor authenticationin ssh, 154–156
One-Time Password, see OTP
one-time passwords, see passwords, one-timeonion, see also garlicches doesn’t like, 287
open (program), 127
open relays, 43, 204
Open Shortest Path First, see OSPF
open source, 261
discussion of, 270
OpenBSD, 261, 270
field stripping, 266
OpenPGP, 327
OpenSSH (program), 61, 154, 270, 275
OpenSSL (program), 89
OracleSQL*Net, 68–69
passwords sniffed by dsniff, 129
oracles, 337
Orange Book, 11, 102, 261
access controls, 11
and the Morris Worm, 102
auditing, 11
ORG (host), 78

Index420
OS/X, 270
field stripping, 266
OS/X.2, 220
OSF, 48
OSPF (Open Shortest Path First), 29
authentication, 29
passwords sniffed by dsniff, 129
OS X, 220
OTP (One-Time Password), 98, 104, 146
Oulu University, 62
OUR - DNS (host), 184
OUR - GW (host), 177
OURHOST (host), 178
outgoing
access policy, 184
laundering calls, 8mail headers, 42
packet filtering, 178
restrictions, 7, 8
UDP packets, 208
output feedback, see OFB
outside world, xviii

p2p, 69
packet filtering, 175, 176–185, 207
block UDP port 2049, 52
bridge, 160, 161
by subnet, 178
CERT recommendations, 350
departmental firewalls, 257
DNS, 184, 185, 198–201
dynamic, 175, 188–193
asymmetric routes and, 191
safety of, 193
erroneous, 178
fragmentation, 228–229
high port numbers, 67
ICMP, 209
IP fragmentation, 228
MBone can subvert, 67
outbound calls, 178
performance, 185reject packets with options, 29
removed or erroneous, 9
requires expertise, 177routing, 182–183, 235

RPC, 188
rpcbind, 50
sample configurations, 184
TCP considerations, 178
UDP, 207–208
UDP is very hard, 207
XDR is hard, 48
packet storms, 72
packet telescope, 116
pages (directory), 166
Palm Pilot, 142
palm tops
storing passwords on, 142
viruses in, 131
PAM (Pluggable Authentication Module), 158
ssh and, 158
Panix, 109, 111, 112
paranoia, 9, 180
Parseghian, Pat, 302
Passface, 142
passwd (file), 56
passwd (program), 293
password safe (program), 142
passwords, 95–98, 138–147
aging is bad, 138–140
converted to Kerberos key, 315
cracking, 98, 288, 317
diceware, 142–143
files
Berferd wanted to modify, 290
bogus, 57, 288
distributed by NIS, 50
in FTP directory, 56
shadow, 98
simulated for Berferd, 294
stealing, 98
gateway administrative, 160
given out by NIS, 50
guessing, 53, 64, 96
by Berferd, 287
with finger information, 105
hidden costs of, 143
human choose lousy, 96
in exponential key exchange, 344
in router configuration files, 53
keyrings, 142
keys generated from, 15

Index421
Lamport’s algorithm, 146–147
list needed by the authors, 141
machine-chosen, 139
not reliable on tapped lines, 59
null root, 272
on different hosts, 99
one-time, 59, 144–147, 302, 310, 342
challenge/response, 145–147
don’t stop TCP hijacking, 59
Plan 9 uses, 310
races, 104remote console access with, 272
optimum length, 97
poorly chosen, 14
protecting, 98
shadow, 50, 98
sniffing, 96, 310
stealing, 29, 58–59, 96, 99, 128, 160
big-time, 187
by monitoring, 103
time-based, 144–145
user-chosen, 138
Path MTU discovery, see ICMP, messages,
path MTU discovery
PAYPAI . COM (host), 325
PC, 59, 103, 146, 184
PC cardsmart cards, 147
VPN boxes, 243
PCLAB - NET (host), 184
peer-to-peer
file transfers, 192
networking, 69–70
large networks not suitable for
Kerberos, 317
possible IPv6 application, 330
security doesn’t scale well, 69
NTP, 208
SIP phones, 47
SOAP, 235
with firewalls, 46
worm network, 111
Pentium, 266
perimeter
security, 10–11
too large, 11Perlscriptgenerated by httpd, 66
implements a Web server, 45
scripts
CGI scripts, 166
used for CGI scripts, 86
perl (program), 219
personal identification number, see PIN
pessimism, 11
PGP (Pretty Good Privacy), 326
and transmission security, 327
attachments, 205
cryptology, 327
file encryption, 57
keyrings
cracking, 129
keys encrypted with a passphrase, 139, 142
public key for contacting hackers, 302
philosophy, 178
authentication, 99–100
clients vs. servers, 85
defense in depth, 310
least privilege, 5, 102, 262
repeated warnings, 79
user security specifications, 83
phone bookdetermine organizational structure with,
105
network service, xvii
online, 105
phone connections
eavesdropping on, 256
PHP (PHP Hypertext Preprocessor), 86
PHP Hypertext Preprocessor, see PHP
Phrack, 130, 349
physical access, 260
alternatives to, 271
host administrators should use, 260
reading password posted on a terminal, 99
to console, 122
physical perimeter, xvii
PIN (personal identification number), 146, 147,
342
ping, see ICMP, messages, Echo Request
ping, 160
ping (program), 27, 113, 160, 183, 209, 215,
240, 248Index422
Ping of Death, see hacking tools, Ping of Deathping6 (program), 126
pirated software, 56
Piscitello, David M., 28
PKI (Public Key Infrastructure), 30, 150–151
PKIX (Public Key Infrastructure (X.509)), 322
plaintext, 335
Plan 9, 310
authentication, 310
playback monitored terminal sessions, 296
PLAYCRITTER . COM (host), 90
Pluggable Authentication Module, see PAM
point firewalls, 258
Point-to-Point Protocol, see PPP
Point-to-Point Tunneling Protocol, see PPTP
police, xix
policydefault, 10
disconnection, 9
firewall, 54
importing foreign software, 7
made by users, 60
outgoing traffic, 7
personal use, 7
POP3, 44–45
APOP authentication, 45, 145, 204
filtering, 204
on medium-security hosts, 255
over SSL on port 995, 171
safe implementation of, 168–169
SSL and, 45
pop3 (program), 145, 149
POP3S, 171
PORT (program), 228
PORT, 202
port scanfor RPC services, 50
port scanners, 121–122
SYN only, 122
portmapper (program), 48, 49
postern gate, see back doors
postfix, 168
postfix (program), 126, 168
PostgreSQL
passwords sniffed by dsniff, 129
postmasterknows SMTP commands, 42

located with SMTP VRFY command, 42
PostScript
called by MIME, 44
can be dangerous, 44
ppp (program), 126, 145
PPP (Point-to-Point Protocol), 235
PPTP (Point-to-Point Tunneling Protocol), 235,
242
encrypted, 271
MS-CHAP
passwords sniffed by dsniff, 129
pre-IV, 326
predictions, 329–332
DNSsec, 330
from the first edition, xiv
Presotto, Dave, 187, 262
Pretty Good Privacy, see PGP
prime numbers, 343
privacy, 16, 326
private address space, 37
choosing, 183
privileged ports, 48
programming advice, 102–103
Project Athena, 314
promiscuous mode, 182
propeller-heads, 122
protocolencapsulation, 234
failures, 104–105
layers, 19
proprietary, 68–69
protocolsmDNS, 264
NetInfo, 264
Provos, Niels, 275, 282
proxies, 214–215
DNS, 198, 207
for ActiveX, 202
FTP, 189, 202
H.323, 208, 215
scan for malware, 202
transparent, 215
Web, 202
ps
ignores hacker’s program, 127
ps (program), 127, 267, 292, 295, 297, 303

Index423
PSTN (Public Switched Telephone Network),
271
public key, see cryptography, public key
Public Key Infrastructure, see PKI
Public Key Infrastructure (X.509), see PKIX
Public Switched Telephone Network, see PSTN
Puddin’head Wilson, 279
Punoval, Theophilus, 159
putty (program), 61
puzzle palace, see National Security Agency
pwd.db (file), 166
Python, Monty, 239

Q.931, 46
quota (program), 126

r-commands, 59–61
authentication rules, 59
RA (Router Advertisement), 36
races
booting a firewall, 220
RADIUS (Remote Authentication Dial In User
Service), 34, 148
radiusniff (program), 123
Rainbow Series, 101
random numbers
generating, 340
in attack packets, 111
NFS file handles, 51
Ranum, Marcus, 166, 167, 228
Ranum’s Law, 202, 204
rcp (program), 61, 126, 322
rdist (program), 61, 154, 274
RDX, see cclotrimethylenetrinitramine207
read (program), 88
Real Networks, 68
Real-Time Transport Protocol, see RTP
RealAudio, 68
filtering, 208
RealPlayer (program), 274
Received:, 33
recursion, see recursion
Red Hat Linux, 261
Red Hat Package Manager, see RPM
Reed, Darren, 220

regression testing, 231
relay, see gateways, relay services
Remote Authentication Dial In User Service, see
RADIUS
Remote Procedure Call, see RPC
Rendezvous (program), 264
replay attacks, see attacks, replay
replicated firewalls, 191–193
resolv.conf (file), 200
resource record, see RR
retarget (program), 169
rexecd (program), 96
RFC 822, 185, 289, 291
RFC 1122, 29
RFC 1123, 24
RFC 1149, 235
RFC 1918, 176, 183, 242, 249
typical address usage on corporate
networks, 254
RFC 1948, 25
RFC 2549, 235
RFC 2822, 43
RFC 3056, 37
RFC 3195, 159
RhostsRSAAuthentication, 154
RIP (Routing Information Protocol), 29
passwords sniffed by dsniff, 129
Risks Forum, 350
Ritchie, Dennis, 266
Rivest, Ron, 339, 343
Riyadh, 292
rkdet (program), 125rld (program), 163
rlogin (program), xiii, 11, 13, 32, 59–61, 89,
126, 127, 138, 154, 168, 183, 292, 322,
387
rlogin.myhost (account), 314
rlogind (program), 29, 61
rm (program), 16, 126, 294
rm -rf /, 294roach motel, see jail partition
Roesch, Martin, 282
root (account), 11, 23, 43, 45, 50, 51, 55, 56, 60,
61, 66, 71, 103, 121, 123–128, 138,
153–155, 158, 162–165, 168–170, 210,
264, 269, 272, 275, 288, 290, 294, 298,
303, 304, 306, 311, 314

Index424
root accesseasy to get in U NIX, 311
root partition, 273
rooted domain name, 32
rootkit, 125–126, 128route (program), 126route squatting, 183routed (program), 268
ROUTER (host), 181
Router Advertisement, see RA
routers, 21
access to network provider’s, 181booted with TFTP, 52
configuration files, 53
deflecting routing attacks, 29
multicasting, 67
network provider’s, 53
packet filtering, 177
performance, 185predictions about security, 331
replaced every 18 months, 329
swamped by UDP packets, 27
routing, 28–29
asymmetric, 28, 160
can’t eliminate, 192
dynamic packet filters and, 191
egress filtering and, 115with dynamic packet filters, 191
attacks, see attacks, routing
between companies through a home
network, 241
CIDR, 21
default route, 182
filtering, see packet filtering, routing
ICMP can change, 27
IPv6 prefix announcements, 36
leaks, 182, 236, 248, 251loose source, 29
on intranets, 249
protocolIS-IS, 29
protocols, 29
static, 268
subversion by route confusion, 183
trouble reporting with ICMP, 27
Routing Information Protocol, see RIP
RPC (Remote Procedure Call), 47–52

authentication, 48
Microsoft uses, 47
procedure number, 48
program number, 48
secure, 48
DCE use of, 48
sequence number, 48
sequence number vulnerability, 104stub routines, 47
uses random port numbers, 208
rpcbind, 47–50
rpcbindforwards screened requests, 103
indirect calls, 50
table of sample services, 49
rpcbind (program), 48–50, 52, 69, 267
rpcinfo (program), 48
RPM (Red Hat Package Manager), 270
RR (resource record), 31
RS-232
console switch, 272
RSA, 327, 342–343
RSA Security, 326
RSADSI, 339
rsh (program), 56, 59–61, 98, 103, 126, 154,
322, 387
rshd (program), 29
rstatd (program), 123, 267
rsync (program), 57, 154, 156, 193, 274
RTP (Real-Time Transport Protocol), 47
Rubin
Ann, 2
Benny, 2
Elana, 2
Mendl, 2
Tamara, 2
RUBINLAP (host), 217
rulesets, 212–214

S-BGP, 30
S-box (substitution box), 338
s.c (program), 307
S/Key, 146
S/MIME, 326
encryption, 326–327
transmission security, 327

Index425
SA (security association), 322
SAC (Strategic Air Command), 231
safe haven, 259
SALES . MYMEGACORP. COM (host), 42
Samba
on medium-security hosts, 255
safe implementation of, 169–170
samba (program), 58, 169
sandbox, 82, 162, see also chroot
chroot, 162
Java, 162
SASL (Simple Authentication and Security
Layer), 149
SATAN, 131
satellite links, 318
sbox (program), 86
Schneier, Bruce, 351
Scotland Yard, 16
scp (program), 61, 154, 156, 273
screend (program), 229
script kiddies, 123
SCTP (Stream Control Transmission Protocol),25–27
and SIP, 47
Scuds, 290, 291
SECONDARY (host), 184, 185
secure hash functions, 146, see cryptography,
secure hash functions
secure hosts, 259–277
access to, 271–272
administering, 271–277
definition of, 259
field stripping a U NIX host, 266–270
hardware configuration, 265–266
properties of, 260–265
software guidelines for, 260–262
updating software, 274–275
Web servers, 86–87
Secure Multipurpose Internet Mail Extensions,
see S/MIME
Secure RPC, see RPC, secure
key database, 50
Secure Socket Layer, see SSL
secure software
properties of, 260–262
SecurID, 144
security“minimal trust” philosophy, 43
by obscurity, 4, 95, 121
cost of, 8home LAN, 241
host-based, 253–255
layered, 96
policy, 7–10, 13, 56, 177
public information, 119–120
strategies, 11–13
vs. convenience, xvii, 19
security association, see SA
security manager, 81
Security Parameter Index, see SPI
security policy, 7
sample, 215–216
Security Policy Database, see SPD
sed (program), 219
Seiden, Mark, 38
self-defense, 17
sendmail
configuration, 43
DEBUG hole, 287, 288, 294
disabled by removing execute permission,310
hard to configure, 43
most common mailer, 43
non-network security holes, 125, 298
SMTP front ends for, 43
sendmail (program), 126, 168, 267, 310, 312
sendwhale, see sendmail
sequence numbers, 22, see also TCP, sequencenumbers
attacks, 23, 29
initial, 23
vulnerabilities, 104
serial lines, 181
Server Management System, see SMS
Server Message Block, see SMB
Servers, 22
servers
NAS, 265
servicesanonymous FTP, see FTP, anonymous
small, 71–72
servlets, 82
session directory, 67–68
session ID, 324

Index426
Session Initiation Protocol, see SIP
setgid, 125
setuid, 123–125
setuid (program), 164, 168
setuid, 52, 298
setuid root programs, 124–125
list of possibly extraneous, 126
table of, 124setupsucker (program), 297
SGI, 264
Irix 6.2
inetd.co nf, 269
Irix systems, 264
setuid programs on, 124
SGI MIPS
M/120, 290
SHA, 327
Shadow (program), 159
shadow password file, see passwords, shadow
Shamir, Adi, 343
shared libraries, 164
Apache uses, 165
modified to record password attempts, 128
modified with back doors, 127
shell escapes, 64, 66
shell script
created by sendmail, 293
generated by httpd, 66
hidden in /usr/lib/term/.s, 298
setupsucker, 297
to simulate login, 295
shim, 243
Shimomura, Tsutomu, 64, 289, 296, 308
shopping cart, 77
Shostack, Adam, 170
shunning, 113
shutdown (program), 126
signature, digital, see digital signature
Simple Authentication and Security Layer, see
SASL
Simple Mail Transfer Protocol, see SMTP
Simple Network Management Protocol, see
SNMP, see SNMP
Simple Object Access Protocol, see SOAP
Sinux
setuid programs on, 124
SIP (Session Initiation Protocol), 46, 47

filtering, 208
site-local address, 35
skinny-dipping, 277
Slackware, 261
slapper (program), 117, 171
slashdot, 351
SLASHDOT. ORG (host), 90
sleep (program), 290, 294
SLIP, 126
sliplogin (program), 126
smart cards, 147, 150
attacks on, 147
can store biometric data, 148
handheld readers, 147
PC card readers, 147
smart hub, 160
SMB (Server Message Block), 57–58, notseesmb169, 209
filtering, 209
passwords sniffed by dsniff, 129
smb.conf (file), 169smbd (directory), 169smbd (program), 169
smptd (program), 168
SMS (Server Management System), 193
SMTP (Simple Mail Transfer Protocol), 41–43,
267
commands
DEBUG, 288, 290, 291
EXPN, 42
MAIL FROM, 42
RCPT TO, 288
VRFY, 42
doesn’t have to run as root, 43
filtering, 203–204, 223
open relays, 204
over SSL on port 465 (deprecated), 171
passwords sniffed by dsniff, 129
sample session, 42
sample unfriendly session, 288
spoken by Web browsers, 74
wrapper, 43
SMTP. ATT. COM (host), 32
SMTPS, 171
smtps (program), 224
smurf, see attacks, Smurf
SNA, xviii

Index427
sniffers, 58
sniffing, 58–59
X11 magic cookies, 71
sniffing attacks, xiii
sniffing tools, 123
SNMP (Simple Network Management Protocol),62–63, 326
authentication, 326
community strings, 62
common, 252“public”, 63, 252
GET, 62
GETNEXT, 62
MIBS and, 62
monitoring network elements, 271
SET, 62
shut off, 265
TRAP, 62
version 1, 62–63
version 3, 63, 265, 271
snntp (program), 66
snort, 282–283
sample rules, 283
snort (program), 275, 282, 283, 351
SOAP (Simple Object Access Protocol), 228,
235
tunneling with, 235
social engineering, 98–100, 122, 132with URLs, 78
SOCKS, 187
diagram of a typical connection, 187
passwords sniffed by dsniff, 129
socks (program), 90
softwareanti-virus, 106–107
evaluating, 155loading and upgrading, 270
software engineering, 102
Software Engineering Notes, 350
software tools, 153–171
network monitoring, 159–162
Solaris, 63
field stripping, 267
SONET, 20Song, Dug, 129
source routing
blocking, 183

Southwestern Bell, 248
space station, 67
Spafford, Gene, 111
spam, 14, 109, 223
filteringwith postfix, 168
spamming, 108
SPARC, 266
SPD (Security Policy Database), 320
SPI (Security Parameter Index), 240, 318
spiderweb, 19
SPIGOT (host), 177
spoofing
ARP, 22, 34, 118, 160
backscatter and, 116–117
DNS, 32, 59, 330
easy with UDP, 27
firewall rules to prevent, 180
firewalls to prevent, 180
IP, 20, 116
IP source addresses, xiii, 48, 60, 71, 72,
104, 149, 156, 161
by ISP customers, 115
DOS attacks, 110
in DOS attacks, 107
mail addresses, 99
the current time, 337
tracing back, 114
UDP source ports, 207
spooling, needs disk space, 268
sprintf (program), 155
spyware, 69
SQUEAMISH . CS . BIG . EDU (host), 32
src/httpd (program), 165
Ssh (program), 157
ssh, 61–62
admin access to VPN device, 244
authentication shortcomings, 157–158
configuration, 61–62
cryptology of, 322–323
cvs and, 238
DSA authentication, 156
filtering, 206
on highly-secure hosts, 255
one-factor authentication, 154–156
problems with, 61–62
protocol 2, 154Index428
protocol failure with NFS, 105
protocols, 61
server authentication, 158
tunneling IP packets over, 243
tunneling X11, 71
two-factor authentication, 157
UsePrivilegeSeparation, 158
Windows implementation putty, 61
ssh (program), 15, 39, 57, 59, 61, 62, 71, 105,
129, 154, 156–158, 188, 199, 203, 204,
206, 210, 219, 222, 238, 243, 244, 253,
255, 271, 274, 275, 277, 322, 323
ssh-agent (program), 61, 323
ssh-keygen (program), 156
ssh config (file), 61
sshd (program), 61, 274
sshd config (file), 61, 156
sshmitm (program), 158
SSL (Secure Socket Layer), 10, 77
cryptology of, 323–325
instant messaging, 46
other protocols over, 171
POP3 and, 45
protocol overview, 324–325
security, 325
version 2 enabled in shipped Web browsers,
83
Web browsers and, 77
with sslwrap, 170–171
SSLtelnet (program), 59
sslwrap, 170–171
sslwrap (program), 169–171
Stacheldraht, 111
stack-smashing, 100, 167
IMAP server, 283
rpcbind, 50
snort can detect attempts, 282
in fingerd, 100
in rstatd, 123
in syslog, 158
in the shell read command, 88
not likely in Java, 210
weird hardware frustrates, 266
stance, 9–10, 188, 208
Stanford University, 288, 289, 291–293, 296,
297
Stazzone, Anthony, 42

stdio (program), 164stel (program), 59
stelnet (program), 59
stereotyped beginnings, 340
Stevens, W. Richard, 19
Stoll, Cliff, 159, 293
Stornetta, W, 347
Strategic Air Command, see SAC
strcat (program), 155
strcpy (program), 155
stream cipher
used by WEP, 39
Stream Control Transmission Protocol, see
SCTPstrings (program), 127
StrongARM, 244
stub routines, 47
stunnel (program), 170su (program), 96, 125, 265
substitution box, see S-box
subversion by route confusion, 183
suexec (program), 165, 167
sulfnbk.exe (program), 100
Sun, 220
setuid programs on, 124
supercomputer, 7
Sweden, 299
Sybase SQL
passwords sniffed by dsniff, 129
Symantec pcAnywhere
passwords sniffed by dsniff, 129
Syslog (program), 272
syslog, 158–159
Macintosh uses, 264
syslog (program), 126, 264
syslogd (program), 158
System V
ps command, 292
Release 4
mailer, 288

tail -f (program), 292
talk (program), 291
tar (program), 273
targets of opportunity, 106, 262

Index429
TCB (Trusted Computing Base), 102, 163, 261,
331
TCP (Transmission Control Protocol), 22–24
listen, 22
acknowledgment number, 22
circuit gateways, see gateways, circuit level
close, 24
filtering, 202–203, see also packet filtering
considerations, 178
policy discussion, 203
half-opened
hiding probes with, 122
half-opened connections, 23
protocol change proposal, 116
SYN attacks and, 109
header bits
ACK, 178, 188, 207
RST, 178
hijacking, xiii, 59
encryption defeats, 130
encryption prevents, 118
network monitors can promote, 160
of X11 sessions, 71
one-time passwords don’t stop, 59
SASL alone doesn’t prevent, 149
tools available, 71
tools for, 118
was theoretical, 130
logging, 187
open, 23–24
initial sequence numbers, 23
SYN attacks and, 23
ports, see TCP ports
reliable delivery, 22
sequence number, 22, 104attacks, 23, 104, 118
DOS attacks and, 111
idiosyncratic, 111
initial, 23, 104
leaking, 71
predicting, 23
visualization of generation algorithms,
25
server ports, 22
servers, 22session, 24
small services, 71–72, 79

statesTIMEWAIT, 53
tunnelingwith ssh, 61
with PPP, 235
won’t continue a non-existent session, 178
wrappers, see TCP wrappers
TCP ports, 22113 (identd), 217
137–139 (NetBIOS), 263
143 (IMAP4), 283
20 (FTP-data), 53, 103
6000– (X11), 70
80 (HTTP), 165
less than 1024, 23
privileged, 23, 59
scanning, 106
TCP wrappers, see wrappers
TCP/IP, 19
TCPA (Trusted Computing Platform Alliance),331
tcpdump (program), 123, 159, 214, 226, 275,
282, 295, 296, 407
tcprelay (program), 187
tcptraceroute (program), 160
Telcordia, 146
telecommuting, 234, 239–242
telephony, 46–47
telnet, 58–59
over SSL on port 992, 171
passwords sniffed by dsniff, 129
telnet (program), xiii, 10, 54, 55, 58–60, 65, 113,
138, 144, 149, 182, 184, 187, 219, 230,
235, 271, 310, 312, 322
telnetd
back door in, 127
telnetd (program), 127
telnets, 171
TEMPEST, see electronic emissions
Temporal Key Integrity Protocol, see TKIP
Teredo, 37
terminal, xvii
terminal server, 289
terminology, xix
Texas A&M University, 289
TFN (Tribe Flood Network), 110
TFTP (Trivial File Transfer Protocol), 52–53

Index430
blocked from outside at a university, 184router configuration and, 53
tftpd (program), 98
TGS (Ticket-Granting Server), 314–316
thanks, xx
The North American Network Operators’ Group,
see NANOG
THEIRHOST (host), 178
This is not a virus.exe (file), 207
Thompson, Ken, 98, 99
ticket, 315–317
Kerberos ticket-granting ticket, 317
ticket-granting, 315, 316
Ticket-Granting Server, see TGS
tiger teams, 132–133, 231
time (program), 71
time-to-live, see TTL
timedc (program), 126
timestamp
based on ntp, 63changing a file’s, 63
digital, 347
Kerberos, 315
SNMP, 326
synchronizing logs, 63
useful in cryptographic protocols, 63
timestamps, see cryptography, timestamps
TIS, 211, see Trusted Information Systems
TiVo, 274, 331
TKIP (Temporal Key Integrity Protocol), 39–40
WEP replaced by, 39
TLS (Transport Layer Security), 323
token, see authenticator, handheld, 145
tools
hacking, see hacking, tools
network administration, 160–162
topology, 182
traceroute6 (program), 126
traceroute, 160
traceroute (program), 21, 27, 30, 121, 160, 183,
209, 215, 217, 230, 280
traceroute-as (program), 31
traffic
analysis, 186, 318, 320
incoming, 7
shaping, 220transitive trust, 11, 13, 60, 179, 249

Transmission Control Protocol, see TCP
transmission error, see error propagation
Transport Layer Security, see TLS
traps, see honeypots
Tribe Flood Network, see TFN
Trickey, Howard, 187
Trinoo, 111
trinoo, see hacking tools, trinoo
Tripwire (program), 275
trivestiture, xiii
Trivial File Transfer Protocol, see TFTP
Trojantypographical errors, 123
Trojan horsein OpenSSH, 275
in released software, 275
Tru64
setuid programs on, 124
trust
asymmetric, 156
trust graph, 327
Trusted Computing Base, see TCB
trusted computing base, 102
trusted computing base,, 163
Trusted Computing Platform Alliance, see TCPA
trusted path, 11
TTL (time-to-live), 160, see IP, TTL fieldtunnel, 233
tunneling, 66, 67, 234–236, 238
encrypted, 183
IP level, 319
IP over IP, 235
L2TP, 235
PPTP, 235
TCP with PPP, 235
through ssh, 243
UDP packets, 188with SOAP, 235
tunnels, 234–236
bypassing firewalls, 235
diverting traffic through, 30
DNS and, 239
GRE, 30
IPsec
resists connection hijacking, 118
to access selected parts of intranets, 249
troubles on Windows hosts, 243

Index431
TV, 291
two-factor authentication, 137
in ssh, 157

U.S. Navy, 261
UDP (User Datagram Protocol), 27
ban outgoing packets, 208
easy to spoof, 27
echo service, 207
filtering, 207–208
no flow control, 27
packet storms, 72
RealAudio and, 68
safe filtering is hard, 207
small services, 71–72
suitable for query/response applications, 27
tunneling, 188
UDP ports(32769–65535) MBone, 672049 (NFS), 52
3544 (Teredo), 37
53 (DNS), 170, 201
less than 1024, 23
MBone, 67
multicast destinations, 67
random, 67
scanning, 106
spoofing, 207
syslog, 158
ukase, see edict
Ultrix, 302, 306, 310, 311
Uniform Resource Locator, see URL
uninterruptible power supply, see UPS
University of Michigan, 275
UNKNOWN. FLEEBLE . COM (host), 201
upas (program), 262
UPS (uninterruptible power supply), 193
Urban, M., see fonts, Tengwar
Urban, Michael, 435
URL (Uniform Resource Locator), 65, 78–79
can be dangerous, 65
invasive, 79
on beer bottles, 3
USENET, see netnews
Usenix, 295
UsePrivilegeSeparation, 428

User Datagram Protocol, see UDP
utmp
altering, 126
utmp (file), 126, 127, 295–297
utmpx (file), 126
uucp account, 125, 297
uucp program, 60, 98
uucp (account), 60
uucp (program), 60, 67
Van Dyke, Jerry, 291
Venema, Wietse, 64, 168, 262, 297, 299
Verisign, 80
version-rollback attacks, 45
virtual circuit, 20, 22
virtual private network, see VPN
Virus construction kits, see hacking tools, Virus
construction kits
viruses, 17, 106–107
anti-virus software, 106–107
checking, 206–207
IBM Christmas Card, 106
infecting stolen software with, 56
losing the arms race with, 331
scanning for, 263
spread by e-mail, 44
urban legends as, 106
voice print, 147
VPN (virtual private network), xv, 233, 236–242
address assignment problems, 239–241
as firewall, 258
DNSsec and, 239
for accessing past departmental firewalls,257
in hardware, 244
in software, 243
susceptible to viruses and Trojans, 243
telecommuting with, 239–242
tunnels
replicated firewalls and, 192
used by joint ventures, 238
YourKey, 244
VRRP
passwords sniffed by dsniff, 129
w (program), 295

Index432
W3C (World Wide Web Consortium), 235
Wagner, David, 38, 159
WAN, 320
war dialing, 121, 248
war drive, 242
war driving, 38
warez, 56, 349
Warrell, C., xx
weather forecasts, interrupted, 16
Web, 73–91
basic authentication, 85
digest authentication, 85
hijacking, 84
protocols, 74–77
search engines
finding hacking tools, 128
Web browsers, 83–85
ActiveX and, 80
bypassing disabled JavaScript in, 83
FTP and, 77
have insecure ciphersuites enabled, 83
Java and, 80–82
plugins, 264, 277
recommendations, 84–85
risks to, 79–85
S/MIME in, 326
shipped with SSL ver. 2 enabled, 83
SSL and, 77
Web bugs, 79, 205
web of mistrust, 111
web of trust, 327
Web proxy, 90
Web servers
access controls, 85
Apache, 165–167
basic authentication, 85
choice of, 87–89
chroot environment, 66
database access by, 91
locating, 89–90
provisioning by users, 156risks to, 85–87
safe configuration, 165–166
sample of a very small one, 88
scripting, 86
securing, 86–87
Web services, 65–66

WEP (Wired Equivalent Privacy), 38–40, 318
protocol failure, 105
security flaws in, 38–39
TKIP replaced, 39
WEPCrack (program), 39
white box testing, 230
WHITEHOUSE . COM (host), 78
WHITEHOUSE . ORG (host), 78
who (program), 126, 127, 295
whois, 64–65
whois (program), 64, 299
WiFi, see 802.11
Wilson, Norman, 167
WILYHACKER . COM (host), 78
Windows, 138, 175, 205, 243, 263
crashed by nmap, 130
file and printer sharing, 58
not suitable for high-security hosts, 255
percent found on intranets, 252
spyware on, 69
susceptible to worms, 206
target for virus writers, 106
tightening up, 263–264
troubles with IPsec, 243
Windows 2000
Kerberos in, 313
Windows 3.1, 263
Windows 95, 263
Windows NT, 138
as a TCB, 261
Lan Manager
weak authentication, 169
LanManager
dictionary attacks on, 138
Windows XP
developer support for IPv6, 329
Wired Equivalent Privacy, see WEP
Wired magazine, 309
wireless, 38–40
base stations, 247, 265
contain firewalls, 175
find with war driving, 242
in the home, 239
World Wide Web, see WWWWorld Wide Web Consortium, see W3C
worms, 106–107
blocking, 206–207

Index433
Code Red, 87, 258
creating Botnets, 117cross-platform, 106
Love Bug, 243
Melissa, 106, 205, 243, 253
Morris, 11, 102, 112, 262
Orange Book would not have stopped,
102
Nimda, 83, 87
Slapper, 111
spread by e-mail, 44
wrappers
alternate TCP ports and, 171
CGI, 86, 166–167
inetd, 154
SMTP, 43
Xwrapper for X11, 125
wtmp (file), 127
wu-ftpd (program), 167
WWW (World Wide Web), 65, 66
query scripts, 66
WWW. ALTAVISTA . COM (host), 78
WWW. ALTAVISTA . DIGITAL . COM (host), 78
WWW. APACHE . ORG (host), 165
WWW. NATO . INT (host), 288
WWW. PLAYGERBIL . COM (host), 79

X Display Manager Control Protocol, see
XDMCP
X.25, 182
X . CS . BIG . EDU . (host), 32
X . TRUSTED . EDU (host), 199
X11, 70–71
call with xwrapper, 125challenge/response security scheme, 71
filtering, 209
font library accessed through TFTP, 52
Kerberos version, 71
magic cookies, 71
must provide own authentication, 103

not handled well by packet filters, 188
passwords sniffed by dsniff, 129
terminals booted with TFTP, 52
ssh, 71
tunnelingwith ssh, 61, 71
with IPsec, 71
used to snatch passwords, 98
X11 (program), 125
xauth (program), 71
Xbreaky (program), 270
xdm, 71
xdm (program), 71
XDMCP (X Display Manager Control Protocol),71
XDR (External Data Representation), 48
xforward (program), 188
xhost (program), 71
xlogin (program), 71
XNS, xviii
xterm (program), 262
XUNET project, 301
Xwrapper (program), 125
xwrapper (program), 433

yacc (program), 102
Yellow Pages, 50
Ylönen, Tatu, 61
YourKey VPN hardware, 244
YP, 50
YP/NIS
passwords sniffed by dsniff, 129
ypchfn (program), 126
ypchpass (program), 126
ypchsh (program), 126
yppasswd (program), 126

Zalewski, Michal, 24
zombies, 110, 117
Zonealarm (program), 226