[asterisk-security] AST-2016-003: Remote crash vulnerability when receiving UDPTL FAX data.

[Asterisk Security Team]

               Asterisk Project Security Advisory - AST-2016-003

         Product        Asterisk                                              
         Summary        Remote crash vulnerability when receiving UDPTL FAX   
                        data.                                                 
    Nature of Advisory  Denial of Service                                     
      Susceptibility    Remote Authenticated Sessions                         
         Severity       Minor                                                 
      Exploits Known    Yes                                                   
       Reported On      December 2, 2015                                      
       Reported By      Walter Dokes, Torrey Searle                           
        Posted On       February 3, 2016                                      
     Last Updated On    February 3, 2016                                      
     Advisory Contact   Richard Mudgett <rmudgett AT digium DOT com>          
         CVE Name       Pending                                               

    Description  If no UDPTL packets are lost there is no problem. However,   
                 a lost packet causes Asterisk to use the available error     
                 correcting redundancy packets. If those redundancy packets   
                 have zero length then Asterisk uses an uninitialized buffer  
                 pointer and length value which can cause invalid memory      
                 accesses later when the packet is copied.                    

    Resolution  Upgrade to a released version with the fix incorporated or    
                apply patch.                                                  

                               Affected Versions       
                         Product                       Release  
                                                       Series   
                  Asterisk Open Source                  1.8.x   All versions  
                  Asterisk Open Source                  11.x    All versions  
                  Asterisk Open Source                  12.x    All versions  
                  Asterisk Open Source                  13.x    All versions  
                   Certified Asterisk                  1.8.28   All versions  
                   Certified Asterisk                   11.6    All versions  
                   Certified Asterisk                   13.1    All versions  

                                  Corrected In
          Product                              Release                        
    Asterisk Open Source                   11.21.1, 13.7.1                    
     Certified Asterisk                11.6-cert12, 13.1-cert3                

                                      Patches                          
                                 SVN URL                               Revision  
   http://downloads.asterisk.org/pub/security/AST-2016-003-1.8.28.diff Certified 
                                                                       Asterisk  
                                                                       1.8.28    
   http://downloads.asterisk.org/pub/security/AST-2016-003-11.6.diff   Certified 
                                                                       Asterisk  
                                                                       11.6      
   http://downloads.asterisk.org/pub/security/AST-2016-003-13.1.diff   Certified 
                                                                       Asterisk  
                                                                       13.1      
   http://downloads.asterisk.org/pub/security/AST-2016-003-1.8.diff    Asterisk  
                                                                       1.8       
   http://downloads.asterisk.org/pub/security/AST-2016-003-11.diff     Asterisk  
                                                                       11        
   http://downloads.asterisk.org/pub/security/AST-2016-003-12.diff     Asterisk  
                                                                       12        
   http://downloads.asterisk.org/pub/security/AST-2016-003-13.diff     Asterisk  
                                                                       13        

    Links  https://issues.asterisk.org/jira/browse/ASTERISK-25603             

    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-2016-003.pdf and             
    http://downloads.digium.com/pub/security/AST-2016-003.html                

                                Revision History
          Date            Editor                  Revisions Made              
    December 7, 2015  Richard Mudgett  Initial document created               

               Asterisk Project Security Advisory - AST-2016-003
              Copyright (c) 2015 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.