[asterisk-security] AST-2012-007: Remote crash vulnerability in IAX2 channel driver.

[Asterisk Security Team]

               Asterisk Project Security Advisory - AST-2012-007

          Product        Asterisk                                             
          Summary        Remote crash vulnerability in IAX2 channel driver.   
    Nature of Advisory   Remote crash                                         
      Susceptibility     Established calls                                    
         Severity        Moderate                                             
      Exploits Known     No                                                   
        Reported On      March 21, 2012                                       
        Reported By      mgrobecker                                           
         Posted On       May 29, 2012                                         
      Last Updated On    May 29, 2012                                         
     Advisory Contact    Richard Mudgett < rmudgett AT digium DOT com >       
         CVE Name        CVE-2012-2947                                        

    Description  A remotely exploitable crash vulnerability exists in the     
                 IAX2 channel driver if an established call is placed on      
                 hold without a suggested music class. For this to occur,     
                 the following must take place:                               
                                                                              
                 1. The setting mohinterpret=passthrough must be set on the   
                 end placing the call on hold.                                
                                                                              
                 2. A call must be established.                               
                                                                              
                 3. The call is placed on hold without a suggested            
                 music-on-hold class name.                                    
                                                                              
                 When these conditions are true, Asterisk will attempt to     
                 use an invalid pointer to a music-on-hold class name. Use    
                 of the invalid pointer will either cause a crash or the      
                 music-on-hold class name will be garbage.                    

    Resolution  Asterisk now sets the extra data parameter to null if the     
                received control frame does not have any extra data.          

                               Affected Versions
                Product              Release Series  
          Certified Asterisk          1.8.11-cert    All versions             
         Asterisk Open Source            1.8.x       All versions             
         Asterisk Open Source             10.x       All versions             

                                  Corrected In
                   Product                              Release               
             Certified Asterisk                      1.8.11-cert2             
            Asterisk Open Source                   1.8.12.1, 10.4.1           

                                       Patches                           
                                SVN URL                                    Revision   
http://downloads.asterisk.org/pub/security/AST-2012-007-1.8.11-cert.diff v1.8.11-cert 
http://downloads.asterisk.org/pub/security/AST-2012-007-1.8.diff         v1.8         
http://downloads.asterisk.org/pub/security/AST-2012-007-10.diff          v10          

       Links     https://issues.asterisk.org/jira/browse/ASTERISK-19597       

    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-2012-007.pdf and             
    http://downloads.digium.com/pub/security/AST-2012-007.html                

                                Revision History
          Date                  Editor                 Revisions Made         
    05/29/2012         Richard Mudgett           Initial release.             

               Asterisk Project Security Advisory - AST-2012-007
              Copyright (c) 2012 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.