S21SEC-037-en: OPAL SIP Protocol Remote Denial of Service

[S21sec Labs <labs () s21sec com>]

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                     - S21Sec Advisory -
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       Title:  OPAL SIP Protocol Remote Denial of Service
           ID:  S21SEC-037-en
Severity:  Medium - Remote DoS
  History:  11.Jun.2007 Vulnerability discovered
                  09.Jul.2007 Vendor contacted
                  15.Aug.2007 Patched
                  17.Sep.2007 New version released

     Scope:  Remote Denial of Service
Platforms:  Any
     Author:  Jose Miguel Esparza (jesparza () s21sec com)
         URL:  http://www.s21sec.com/avisos/s21sec-037-en.txt
 Release:  Public


[ SUMMARY ]

OPAL (Open Phone Abstraction Layer) is an implementation of various  
telephony and video communication
protocols for use over packet based networks. It's based on code from  
the OpenH323 project and adds new
features such as a stream based architecture, better support for re- 
use or removal of sub-components,
and explicit support for additional protocols.


[ AFFECTED VERSIONS ]

Following versions are affected with this issue:

    - OPAL 2.2.8 and prior.

Some applications which use this library are affected too:

    - Ekiga 2.0.9 and prior.


[ DESCRIPTION ]

File:  sippdu.cxx
Function:  SIP_PDU::Read(OpalTransport & transport)
Instruction:  entityBody[contentLength] = '\0';

An insufficient input validation of the Content-Length field of a SIP  
request cause the application to
crash due to a memory mismanagement.


[ WORKAROUND ]

A patch in the url http://openh323.cvs.sourceforge.net/openh323/opal/ 
src/sip/sippdu.cxx?r1=2.83.2.19&r2=2.83.2.20
is available, but upgrading to new version 2.2.10 is recommended.


[ ACKNOWLEDGMENTS ]

This vulnerability have been found and researched by:

    - Jose Miguel Esparza <jesparza () s21sec com> S21sec labs


[ ADDITIONAL INFORMATION ]

This vulnerability has been discovered during the development of the  
network fuzzer Malybuzz, available in the url
http://malybuzz.sourceforge.net/


[ REFERENCES ]

* OpenH323 Project
  http://openh323.sourceforge.net/

* Ekiga
  http://ekiga.org

* S21Sec
  http://www.s21sec.com
  http://blog.s21sec.com

* Malybuzz
  http://malybuzz.sourceforge.net/