[asterisk-security] AST-2014-016: Remote Crash Vulnerability in PJSIP channel driver

[Asterisk Security Team]

               Asterisk Project Security Advisory - AST-2014-016

         Product        Asterisk                                              
         Summary        Remote Crash Vulnerability in PJSIP channel driver    
    Nature of Advisory  Denial of Service                                     
      Susceptibility    Remote Unauthenticated Sessions                       
         Severity       Critical                                              
      Exploits Known    No                                                    
       Reported On      17 November 2014                                      
       Reported By      Joshua Colp                                           
        Posted On       20 November 2014                                      
     Last Updated On    November 20, 2014                                     
     Advisory Contact   Joshua Colp <jcolp AT digium DOT com>                 
         CVE Name       Pending                                               

    Description  When handling an INVITE with Replaces message the            
                 res_pjsip_refer module incorrectly assumes that it will be   
                 operating on a channel that has just been created. If the    
                 INVITE with Replaces message is sent in-dialog after a       
                 session has been established this assumption will be         
                 incorrect. The res_pjsip_refer module will then hang up a    
                 channel that is actually owned by another thread. When this  
                 other thread attempts to use the just hung up channel it     
                 will end up using freed channel which will likely cause a    
                 crash.                                                       

    Resolution  If REFER support is not required the res_pjsip_refer module   
                can be unloaded to limit exposure otherwise the               
                res_pjsip_refer module has been patched so it will not allow  
                an in-dialog INVITE with Replaces message to be processed.    

                               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-2014-016-12.diff   Asterisk 
                                                                     12       
   http://downloads.asterisk.org/pub/security/AST-2014-016-13.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-2014-016.pdf and             
    http://downloads.digium.com/pub/security/AST-2014-016.html                

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

               Asterisk Project Security Advisory - AST-2014-016
              Copyright (c) 2014 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.