Asterisk Project Security Advisory - ASA-2007-015 +------------------------------------------------------------------------+ | Product | Asterisk | |--------------------+---------------------------------------------------| | Summary | Remote Crash Vulnerability in IAX2 channel driver | |--------------------+---------------------------------------------------| | Nature of Advisory | Denial of Service | |--------------------+---------------------------------------------------| | Susceptibility | Remote Unauthenticated Sessions | |--------------------+---------------------------------------------------| | Severity | Critical | |--------------------+---------------------------------------------------| | Exploits Known | No | |--------------------+---------------------------------------------------| | Reported On | July 13, 2007 | |--------------------+---------------------------------------------------| | Reported By | Chris Clark and Zane Lackey, iSEC Partners | |--------------------+---------------------------------------------------| | Posted On | July 17, 2007 | |--------------------+---------------------------------------------------| | Last Updated On | July 17, 2007 | |--------------------+---------------------------------------------------| | Advisory Contact | Russell Bryant <russell at digium.com> | |--------------------+---------------------------------------------------| | CVE Name | CVE-2007-3763 | +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ | Description | The Asterisk IAX2 channel driver, chan_iax2, has a | | | remotely exploitable crash vulnerability. A NULL pointer | | | exception can occur when Asterisk receives a LAGRQ or | | | LAGRP frame that is part of a valid session and includes | | | information elements. The session used to exploit this | | | issue does not have to be authenticated. It can simply | | | be a NEW packet sent with an invalid username. | | | | | | The code that parses the incoming frame correctly parses | | | the information elements of IAX frames. It then sets a | | | pointer to NULL to indicate that there is not a raw data | | | payload associated with this frame. However, it does not | | | set the variable that indicates the number of bytes in | | | the raw payload back to zero. Since the raw data length | | | is non-zero, the code handling LAGRQ and LAGRP frames | | | tries to copy data from a NULL pointer, causing a crash. | +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ | Resolution | All users that have chan_iax2 enabled should upgrade to | | | the appropriate version listed in the corrected in | | | section of this advisory. | +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ | Affected Versions | |------------------------------------------------------------------------| | Product | Release | | | | Series | | |----------------------------------+-------------+-----------------------| | Asterisk Open Source | 1.0.x | All versions | |----------------------------------+-------------+-----------------------| | Asterisk Open Source | 1.2.x | All versions prior to | | | | 1.2.22 | |----------------------------------+-------------+-----------------------| | Asterisk Open Source | 1.4.x | All versions prior to | | | | 1.4.8 | |----------------------------------+-------------+-----------------------| | Asterisk Business Edition | A.x.x | All versions | |----------------------------------+-------------+-----------------------| | Asterisk Business Edition | B.x.x | All versions prior to | | | | B.2.2.1 | |----------------------------------+-------------+-----------------------| | AsteriskNOW | pre-release | All versions prior to | | | | beta7 | |----------------------------------+-------------+-----------------------| | Asterisk Appliance Developer Kit | 0.x.x | All versions prior to | | | | 0.5.0 | |----------------------------------+-------------+-----------------------| | s800i (Asterisk Appliance) | 1.0.x | All versions prior to | | | | 1.0.2 | +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ | Corrected In | |------------------------------------------------------------------------| | Product | Release | |-------------------+----------------------------------------------------| | Asterisk Open | 1.2.22 and 1.4.8, available from | | Source | ftp://ftp.digium.com/pub/telephony/asterisk | |-------------------+----------------------------------------------------| | Asterisk Business | B.2.2.1, available from the Asterisk Business | | Edition | Edition user portal on http://www.digium.com or | | | | | | via Digium Technical Support | |-------------------+----------------------------------------------------| | AsteriskNOW | Beta7, available from http://www.asterisknow.org/. | | | Beta5 and Beta6 users can update using the system | | | update feature in the appliance control panel. | |-------------------+----------------------------------------------------| | Asterisk | 0.5.0, available from | | Appliance | | | Developer Kit | ftp://ftp.digium.com/pub/telephony/aadk/ | |-------------------+----------------------------------------------------| | s800i (Asterisk | 1.0.2 | | Appliance) | | +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ | Links | | +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ | Asterisk Project Security Advisories are posted at | | http://www.asterisk.org/security. | | | | This document may be superseded by later versions; if so, the latest | | version will be posted at | | http://ftp.digium.com/pub/asa/ASA-2007-015.pdf. | +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ | Revision History | |------------------------------------------------------------------------| | Date | Editor | Revisions Made | |-------------------+-------------------------+--------------------------| | July 17, 2007 | russell at digium.com | Initial Release | +------------------------------------------------------------------------+ Asterisk Project Security Advisory - ASA-2007-015 Copyright (c) 2007 Digium, Inc. All Rights Reserved. Permission is hereby granted to distribute and publish this advisory in its original, unaltered form.