ASTERWEB Blog

AST-2016-004: Long Contact URIs in REGISTER requests can crash Asterisk

               Asterisk Project Security Advisory - AST-2016-004

         Product        Asterisk

         Summary        Long Contact URIs in REGISTER requests can crash

                        Asterisk

    Nature of Advisory  Remote Crash

      Susceptibility    Remote Authenticated Sessions

         Severity       Major

      Exploits Known    No

       Reported On      January 19, 2016

       Reported By      George Joseph

        Posted On

     Last Updated On    February 10, 2016

     Advisory Contact   Mark Michelson <mmichelson AT digium DOT com>

         CVE Name       
    Description  Asterisk may crash when processing an incoming REGISTER

                 request if that REGISTER contains a Contact header with a

                 lengthy URI.                                                 
                 This crash will only happen for requests that pass

                 authentication. Unauthenticated REGISTER requests will not

                 result in a crash occurring.                                 
                 This vulnerability only affects Asterisk when using PJSIP

                 as its SIP stack. The chan_sip module does not have this

                 problem.                                                     
    Resolution  Measures have been put in place to ensure that REGISTER

                requests with long Contact URIs are rejected instead of

                causing a crash.                                              
                               Affected Versions

                         Product                       Release

                                                       Series

                  Asterisk Open Source                  11.x    Unaffected

                  Asterisk Open Source                  13.x    All versions

                   Certified Asterisk                   11.6    Unaffected

                   Certified Asterisk                   13.1    All versions  
                                  Corrected In

                              Product                              Release

                        Asterisk Open Source                        13.8.1

                         Certified Asterisk                       13.1-cert5  
                                    Patches

                 SVN URL                              Revision                
           Links         
    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-2016-004.pdf and

    http://downloads.digium.com/pub/security/AST-2016-004.html