OSEC

Neohapsis is currently accepting applications for employment. For more information, please visit our website www.neohapsis.com or email hr@neohapsis.com
AST-2008-010: Asterisk IAX 'POKE' resource exhaustion

From: Asterisk Security Team (securityasterisk.org)
Date: Tue Jul 22 2008 - 18:15:49 CDT


               Asterisk Project Security Advisory - AST-2008-010

   +------------------------------------------------------------------------+
   | Product | Asterisk |
   |----------------------+-------------------------------------------------|
   | Summary | Asterisk IAX 'POKE' resource exhaustion |
   |----------------------+-------------------------------------------------|
   | Nature of Advisory | Denial of service |
   |----------------------+-------------------------------------------------|
   | Susceptibility | Remote Unauthenticated Sessions |
   |----------------------+-------------------------------------------------|
   | Severity | Critical |
   |----------------------+-------------------------------------------------|
   | Exploits Known | Yes |
   |----------------------+-------------------------------------------------|
   | Reported On | July 18, 2008 |
   |----------------------+-------------------------------------------------|
   | Reported By | Jeremy McNamara < jj AT nufone DOT net > |
   |----------------------+-------------------------------------------------|
   | Posted On | July 22, 2008 |
   |----------------------+-------------------------------------------------|
   | Last Updated On | July 22, 2008 |
   |----------------------+-------------------------------------------------|
   | Advisory Contact | Tilghman Lesher < tlesher AT digium DOT com > |
   |----------------------+-------------------------------------------------|
   | CVE Name | CVE-2008-3263 |
   +------------------------------------------------------------------------+

   +------------------------------------------------------------------------+
   | Description | By flooding an Asterisk server with IAX2 'POKE' |
   | | requests, an attacker may eat up all call numbers |
   | | associated with the IAX2 protocol on an Asterisk server |
   | | and prevent other IAX2 calls from getting through. Due |
   | | to the nature of the protocol, IAX2 POKE calls will |
   | | expect an ACK packet in response to the PONG packet sent |
   | | in response to the POKE. While waiting for this ACK |
   | | packet, this dialog consumes an IAX2 call number, as the |
   | | ACK packet must contain the same call number as was |
   | | allocated and sent in the PONG. |
   +------------------------------------------------------------------------+

   +------------------------------------------------------------------------+
   | Resolution | The implementation has been changed to no longer allocate |
   | | an IAX2 call number for POKE requests. Instead, call |
   | | number 1 has been reserved for all responses to POKE |
   | | requests, and ACK packets referencing call number 1 will |
   | | be silently dropped. |
   +------------------------------------------------------------------------+

+---------------------------------------------------------------------------------------------------------------------------------+
|Commentary|This vulnerability was reported to us without exploit code, less than two days before public release, with exploit |
| |code. Additionally, we were not informed of the public release of the exploit code and only learned this fact from a |
| |third party. We reiterate that this is irresponsible security disclosure, and we recommend that in the future, |
| |adequate time be given to fix any such vulnerability. Recommended reading: |
| |http://www.oisafety.org/guidelines/Guidelines%20for%20Security%20Vulnerability%20Reporting%20and%20Response%20V2.0.pdf|
+---------------------------------------------------------------------------------------------------------------------------------+

   +------------------------------------------------------------------------+
   | Affected Versions |
   |------------------------------------------------------------------------|
   | Product | Release | |
   | | Series | |
   |----------------------------------+-------------+-----------------------|
   | Asterisk Open Source | 1.0.x | All versions |
   |----------------------------------+-------------+-----------------------|
   | Asterisk Open Source | 1.2.x | All versions prior to |
   | | | 1.2.30 |
   |----------------------------------+-------------+-----------------------|
   | Asterisk Open Source | 1.4.x | All versions prior to |
   | | | 1.4.21.2 |
   |----------------------------------+-------------+-----------------------|
   | Asterisk Addons | 1.2.x | Not affected |
   |----------------------------------+-------------+-----------------------|
   | Asterisk Addons | 1.4.x | Not affected |
   |----------------------------------+-------------+-----------------------|
   | Asterisk Business Edition | A.x.x | All versions |
   |----------------------------------+-------------+-----------------------|
   | Asterisk Business Edition | B.x.x.x | All versions prior to |
   | | | B.2.5.4 |
   |----------------------------------+-------------+-----------------------|
   | Asterisk Business Edition | C.x.x.x | All versions prior to |
   | | | C.1.10.3 |
   |----------------------------------+-------------+-----------------------|
   | AsteriskNOW | pre-release | All versions |
   |----------------------------------+-------------+-----------------------|
   | Asterisk Appliance Developer Kit | 0.x.x | All versions |
   |----------------------------------+-------------+-----------------------|
   | s800i (Asterisk Appliance) | 1.0.x | All versions prior to |
   | | | 1.2.0.1 |
   +------------------------------------------------------------------------+

   +------------------------------------------------------------------------+
   | Corrected In |
   |------------------------------------------------------------------------|
   | Product | Release |
   |---------------------------------------------+--------------------------|
   | Asterisk Open Source | 1.2.30 |
   |---------------------------------------------+--------------------------|
   | Asterisk Open Source | 1.4.21.2 |
   |---------------------------------------------+--------------------------|
   | Asterisk Business Edition | B.2.5.4 |
   |---------------------------------------------+--------------------------|
   | Asterisk Business Edition | C.1.10.3 |
   |---------------------------------------------+--------------------------|
   | Asterisk Business Edition | C.2.0.3 |
   |---------------------------------------------+--------------------------|
   | s800i (Asterisk Appliance) | 1.2.0.1 |
   +------------------------------------------------------------------------+

+----------------------------------------------------------------------------------------------------------------------------+
|Links|http://www.oisafety.org/guidelines/Guidelines%20for%20Security%20Vulnerability%20Reporting%20and%20Response%20V2.0.pdf|
|-----+----------------------------------------------------------------------------------------------------------------------|
| |http://www.securityfocus.com/bid/30321/info |
+----------------------------------------------------------------------------------------------------------------------------+

   +------------------------------------------------------------------------+
   | 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://downloads.digium.com/pub/security/AST-2008-010.pdf and |
   | http://downloads.digium.com/pub/security/AST-2008-010.html |
   +------------------------------------------------------------------------+

   +------------------------------------------------------------------------+
   | Revision History |
   |------------------------------------------------------------------------|
   | Date | Editor | Revisions Made |
   |-----------------+--------------------+---------------------------------|
   | July 22, 2008 | Tilghman Lesher | Initial release |
   |-----------------+--------------------+---------------------------------|
   | July 22, 2008 | Tilghman Lesher | Revised C.1 version numbers |
   +------------------------------------------------------------------------+

               Asterisk Project Security Advisory - AST-2008-010
              Copyright (c) 2008 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.