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ESB-2014.1636 - [Win][UNIX/Linux] Asterisk: Denial of service - Remote/unauthenticated

Date: 22 September 2014

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             AUSCERT External Security Bulletin Redistribution

             Asterisk Project Security Advisory - AST-2014-009
                             22 September 2014


        AusCERT Security Bulletin Summary

Product:           Asterisk
Publisher:         Digium
Operating System:  Windows
                   UNIX variants (UNIX, Linux, OSX)
Impact/Access:     Denial of Service -- Remote/Unauthenticated
Resolution:        Patch/Upgrade

Original Bulletin:

- --------------------------BEGIN INCLUDED TEXT--------------------

               Asterisk Project Security Advisory - AST-2014-009

         Product        Asterisk                                              
         Summary        Remote crash based on malformed SIP subscription      
    Nature of Advisory  Remotely triggered crash of Asterisk                  
      Susceptibility    Remote authenticated sessions                         
         Severity       Major                                                 
      Exploits Known    No                                                    
       Reported On      30 July, 2014                                         
       Reported By      Mark Michelson                                        
        Posted On       18 September, 2014                                    
     Last Updated On    September 18, 2014                                    
     Advisory Contact   Mark Michelson <mmichelson AT digium DOT com>         
         CVE Name       Pending                                               

    Description  It is possible to trigger a crash in Asterisk by sending a   
                 SIP SUBSCRIBE request with unexpected mixes of headers for   
                 a given event package. The crash occurs because Asterisk     
                 allocates data of one type at one layer and then interprets  
                 the data as a separate type at a different layer. The crash  
                 requires that the SUBSCRIBE be sent from a configured        
                 endpoint, and the SUBSCRIBE must pass any authentication     
                 that has been configured.                                    
                 Note that this crash is Asterisk's PJSIP-based               
                 res_pjsip_pubsub module and not in the old chan_sip module.  

    Resolution  Type-safety has been built into the pubsub API where it       
                previously was absent. A test has been added to the           
                testsuite that previously would have triggered the crash.     

                               Affected Versions      
                        Product                       Release  
                  Asterisk Open Source                 1.8.x   Unaffected     
                  Asterisk Open Source                 11.x    Unaffected     
                  Asterisk Open Source                 12.x    12.1.0 and up  
                   Certified Asterisk                 1.8.15   Unaffected     
                   Certified Asterisk                  11.6    Unaffected     

                                  Corrected In         
                         Product                              Release         
                  Asterisk Open Source                        12.5.1          

                                SVN URL                              Revision   Asterisk 


    Asterisk Project Security Advisories are posted at                                                             
    This document may be superseded by later versions; if so, the latest      
    version will be posted at                                             and                        

                                Revision History
         Date            Editor                  Revisions Made               
    19 August, 2014  Mark Michelson  Initial version of document              

               Asterisk Project Security Advisory - AST-2014-009
              Copyright (c) 2014 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.

- --------------------------END INCLUDED TEXT--------------------

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