[asterisk-security] AST-2021-008: Remote crash when using IAX2 channel driver

[Asterisk Security Team]

               Asterisk Project Security Advisory - AST-2021-008

          Product         Asterisk                                            
          Summary         Remote crash when using IAX2 channel driver         
     Nature of Advisory   Denial of service                                   
       Susceptibility     Remote unauthenticated sessions                     
          Severity        Major                                               
       Exploits Known     No                                                  
        Reported On       April 13, 2021                                      
        Reported By       Michael Welk                                        
         Posted On        
      Last Updated On     July 6, 2021                                        
      Advisory Contact    kharwell AT sangoma DOT com                         
          CVE Name        CVE-2021-32558                                      

      Description     If the IAX2 channel driver receives a packet that       
                      contains an unsupported  media format  it can cause a   
                      crash to occur in Asterisk.                             
    Modules Affected  chan_iax2.c                                             

    Resolution  Checks are now in place that make it so packets containing    
                unsupported media formats are ignored/dropped in the IAX2     
                channel driver. This ensures Asterisk no longer crashes.      

                               Affected Versions
                Product              Release Series  
         Asterisk Open Source             13.x       All versions             
         Asterisk Open Source             16.x       All versions             
         Asterisk Open Source             17.x       All versions             
         Asterisk Open Source             18.x       All versions             
          Certified Asterisk              16.8       All versions             

                                  Corrected In
               Product                              Release                   
        Asterisk Open Source           13.38.3, 16.19.1, 17.9.4, 18.5.1       
         Certified Asterisk                       16.8-cert10                 

                                    Patches                        
                              Patch URL                             Revision  
   http://downloads.digium.com/pub/security/AST-2021-008-13.diff   Asterisk   
                                                                   13         
   http://downloads.digium.com/pub/security/AST-2021-008-16.diff   Asterisk   
                                                                   16         
   http://downloads.digium.com/pub/security/AST-2021-008-17.diff   Asterisk   
                                                                   17         
   http://downloads.digium.com/pub/security/AST-2021-008-18.diff   Asterisk   
                                                                   18         
   http://downloads.digium.com/pub/security/AST-2021-008-16.8.diff Certified  
                                                                   Asterisk   
                                                                   16.8       

     Links   https://issues.asterisk.org/jira/browse/ASTERISK-29392           
                                                                              
             https://downloads.asterisk.org/pub/security/AST-2021-008.html    

    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-2021-008.pdf and             
    http://downloads.digium.com/pub/security/AST-2021-008.html                

                                Revision History
          Date                  Editor                 Revisions Made         
    May 10, 2021       Kevin Harwell             Initial revision             

               Asterisk Project Security Advisory - AST-2021-008
               Copyright © 2021 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.