AST-2014-014: High call load may result in hung channels in ConfBridge.

           Asterisk Project Security Advisory - AST-2014-014

     Product        Asterisk                                              
     Summary        High call load may result in hung channels in         
                    ConfBridge.                                           
Nature of Advisory  Denial of Service                                     
  Susceptibility    Remote Unauthenticated Sessions                       
     Severity       Moderate                                              
  Exploits Known    No                                                    
   Reported On      19 October, 2014                                      
   Reported By      Ben Klang                                             
    Posted On       20 November 2014                                      
 Last Updated On    November 20, 2014                                     
 Advisory Contact   Joshua Colp <jcolp AT digium DOT com>                 
     CVE Name       Pending                                               

Description  The ConfBridge application uses an internal bridging API to  
             implement conference bridges. This internal API uses a       
             state model for channels within the conference bridge and    
             transitions between states as different things occur. Under  
             load it is possible for some state transitions to be         
             delayed causing the channel to transition from being hung    
             up to waiting for media. As the channel has been hung up     
             remotely no further media will arrive and the channel will   
             stay within ConfBridge indefinitely.                         

Resolution  The underlying bridging code that ConfBridge uses has been    
            fixed so state changes can not occur that will take a         
            channel out of the hung up state.                             

                           Affected Versions       
                     Product                       Release  
                                                   Series   
              Asterisk Open Source                  11.x    All versions  
               Certified Asterisk                   11.6    All versions  

                              Corrected In                    
                          Product                              Release    
                    Asterisk Open Source                       11.14.1    
                     Certified Asterisk                       11.6-cert8  

                                 Patches                         
                            SVN URL                              Revision  
http://downloads.asterisk.org/pub/security/AST-2014-014-11.diff  Asterisk  
                                                                    11     

http://downloads.asterisk.org/pub/security/AST-2014-014-11.6.diff Certified
Asterisk
11.6

Links  https://issues.asterisk.org/jira/browse/ASTERISK-24440             

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-2014-014.pdf and             
http://downloads.digium.com/pub/security/AST-2014-014.html                

                            Revision History
      Date           Editor                  Revisions Made               
20 November, 2014  Joshua Colp  Initial Advisory created                  

           Asterisk Project Security Advisory - AST-2014-014
          Copyright (c) 2014 Digium, Inc. All Rights Reserved.

Permission is hereby granted to distribute and publish this advisory in its
original, unaltered form.