[asterisk-users] AST-2017-008: RTP/RTCP information leak

[Asterisk Security Team]

               Asterisk Project Security Advisory - AST-2017-008

         Product        Asterisk                                              
         Summary        RTP/RTCP information leak                             
    Nature of Advisory  Unauthorized data disclosure                          
      Susceptibility    Remote Unauthenticated Sessions                       
         Severity       Critical                                              
      Exploits Known    Yes                                                   
       Reported On      September 1, 2017                                     
       Reported By      Klaus-Peter Junghanns                                 
        Posted On       September 19, 2017                                    
     Last Updated On    September 19, 2017                                    
     Advisory Contact   Richard Mudgett <rmudgett AT digium DOT com>          
         CVE Name       CVE-2017-14099                                        

    Description  This is a follow up advisory to AST-2017-005.                
                                                                              
                 Insufficient RTCP packet validation could allow reading      
                 stale buffer contents and when combined with the “nat” and   
                 “symmetric_rtp” options allow redirecting where Asterisk     
                 sends the next RTCP report.                                  
                                                                              
                 The RTP stream qualification to learn the source address of  
                 media always accepted the first RTP packet as the new        
                 source and allowed what AST-2017-005 was mitigating. The     
                 intent was to qualify a series of packets before accepting   
                 the new source address.                                      

    Resolution  The RTP/RTCP stack will now validate RTCP packets before      
                processing them. Packets failing validation are discarded.    
                RTP stream qualification now requires the intended series of  
                packets from the same address without seeing packets from a   
                different source address to accept a new source address.      

                               Affected Versions       
                         Product                       Release  
                                                       Series   
                  Asterisk Open Source                  11.x    All Releases  
                  Asterisk Open Source                  13.x    All Releases  
                  Asterisk Open Source                  14.x    All Releases  
                   Certified Asterisk                   11.6    All Releases  
                   Certified Asterisk                   13.13   All Releases  

                                  Corrected In
          Product                              Release                        
    Asterisk Open Source               11.25.3, 13.17.2, 14.6.2               
     Certified Asterisk                11.6-cert18, 13.13-cert6               

                                     Patches                          
                                SVN URL                               Revision  
   http://downloads.asterisk.org/pub/security/AST-2017-008-11.diff    Asterisk  
                                                                      11        
   http://downloads.asterisk.org/pub/security/AST-2017-008-13.diff    Asterisk  
                                                                      13        
   http://downloads.asterisk.org/pub/security/AST-2017-008-14.diff    Asterisk  
                                                                      14        
   http://downloads.asterisk.org/pub/security/AST-2017-008-11.6.diff  Certified 
                                                                      Asterisk  
                                                                      11.6      
   http://downloads.asterisk.org/pub/security/AST-2017-008-13.13.diff Certified 
                                                                      Asterisk  
                                                                      13.13     

    Links  https://issues.asterisk.org/jira/browse/ASTERISK-27274             
                                                                              
           https://issues.asterisk.org/jira/browse/ASTERISK-27252             

    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-2017-008.pdf and             
    http://downloads.digium.com/pub/security/AST-2017-008.html                

                                Revision History
       Date         Editor                     Revisions Made                 
    09/15/2017  Richard Mudgett  Initial revision                             
    09/19/2017  Joshua Colp      Added CVE                                    

               Asterisk Project Security Advisory - AST-2017-008
               Copyright © 2017 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.