[asterisk-security] AST-2014-015: Remote Crash Vulnerability in PJSIP channel driver

[Asterisk Security Team]

               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.