AST-2011-014: Remote crash possibility with SIP and the "automon" feature enabled

           Asterisk Project Security Advisory - AST-2011-014

     Product        Asterisk                                              
     Summary        Remote crash possibility with SIP and the "automon"   
                    feature enabled                                       
Nature of Advisory  Remote crash vulnerability in a feature that is       
                    disabled by default                                   
  Susceptibility    Remote unauthenticated sessions                       
     Severity       Moderate                                              
  Exploits Known    Yes                                                   
   Reported On      November 2, 2011                                      
   Reported By      Kristijan Vrban                                       
    Posted On       2011-11-03                                            
 Last Updated On    December 7, 2011                                      
 Advisory Contact   Terry Wilson <[email protected]>                     
     CVE Name       

Description  When the "automon" feature is enabled in features.conf, it   
             is possible to send a sequence of SIP requests that cause    
             Asterisk to dereference a NULL pointer and crash.            

Resolution  Applying the referenced patches that check that the pointer   
            is not NULL before accessing it will resolve the issue. The   
            "automon" feature can be disabled in features.conf as a       
            workaround.                                                   

                           Affected Versions
            Product              Release Series  
     Asterisk Open Source           1.6.2.x      All versions             
     Asterisk Open Source            1.8.x       All versions             

                              Corrected In
               Product                              Release               
        Asterisk Open Source                   1.6.2.21, 1.8.7.2          

                                 Patches                          
                          Download URL                            Revision 

http://downloads.asterisk.org/pub/security/AST-2011-014-1.6.2.diff 1.6.2.20
http://downloads.asterisk.org/pub/security/AST-2011-014-1.8.diff 1.8.7.1

        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://downloads.digium.com/pub/security/AST-2011-014.pdf and             
http://downloads.digium.com/pub/security/AST-2011-014.html                

                            Revision History
       Date                 Editor                 Revisions Made         

           Asterisk Project Security Advisory - AST-2011-014
          Copyright (c) 2011 Digium, Inc. All Rights Reserved.

Permission is hereby granted to distribute and publish this advisory in its
original, unaltered form.