AST-2014-015: Remote Crash Vulnerability in PJSIP channel driver

Asterisk Project Security Advisory - AST-2014-015

         Product        Asterisk
         Summary        Remote Crash Vulnerability in PJSIP channel driver
    Nature of Advisory  Denial of Service
      Susceptibility    Remote Unauthenticated Sessions
         Severity       Moderate
      Exploits Known    No
       Reported On      30 October 2014
       Reported By      Yaron Nahum
        Posted On       20 November 2014
     Last Updated On    November 20, 2014
     Advisory Contact   Joshua Colp <jcolp AT digium DOT com>
         CVE Name       Pending


    Description  The chan_pjsip channel driver uses a queue approach for
                 actions relating to SIP sessions. There exists a race
                 condition where actions may be queued to answer a session
                 or send ringing AFTER a SIP session has been terminated
                 using a CANCEL request. The code will incorrectly assume
                 that the SIP session is still active and attempt to send
                 the SIP response. The PJSIP library does not expect the SIP
                 session to be in the disconnected state when sending the
                 response and asserts.

    Resolution  Asterisk has been patched so any queued actions that occur
                after a SIP session has been disconnected will not execute.

                               Affected Versions
                         Product                       Release
                                                       Series
                  Asterisk Open Source                  12.x    All versions
                  Asterisk Open Source                  13.x    All versions

                                  Corrected In
                            Product                              Release
                      Asterisk Open Source                    12.7.1, 13.0.1

                                    Patches
                                SVN URL                              Revision
   http://downloads.asterisk.org/pub/security/AST-2014-015-12.diff   Asterisk
                                                                     12
   http://downloads.asterisk.org/pub/security/AST-2014-015-13.diff   Asterisk
                                                                     13

    Links  https://issues.asterisk.org/jira/browse/ASTERISK-24471

    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-2014-015.pdf and
    http://downloads.digium.com/pub/security/AST-2014-015.html

                                Revision History
                      Date                       Editor      Revisions Made
    November 20 2014                           Joshua Colp  Initial Revision

               Asterisk Project Security Advisory - AST-2014-015
              Copyright (c) 2014 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.