AST-2012-004: Asterisk Manager User Unauthorized Shell Access

           Asterisk Project Security Advisory - AST-2012-004

      Product         Asterisk                                            
      Summary         Asterisk Manager User Unauthorized Shell Access     
 Nature of Advisory   Permission Escalation                               
   Susceptibility     Remote Authenticated Sessions                       
      Severity        Minor                                               
   Exploits Known     No                                                  
    Reported On       February 23, 2011                                   
    Reported By       David Woolley                                       
     Posted On        April 23, 2012                                      
  Last Updated On     April 23, 2012                                      
  Advisory Contact    Jonathan Rose < jrose AT digium DOT com >           
      CVE Name        

Description  A user of the Asterisk Manager Interface can bypass a        
             security check and execute shell commands when they lack     
             permission to do so. Under normal conditions, a user should  
             only be able to run shell commands if that user has System   
             class authorization. Users could bypass this restriction by  
             using the MixMonitor application with the originate action   
             or by using either the GetVar or Status manager actions in   
             combination with the SHELL and EVAL functions. The patch     
             adds checks in each affected action to verify if a user has  
             System class authorization. If the user does not have those  
             authorizations, Asterisk rejects the action if it detects    
             the use of any functions or applications that run system     
             commands.                                                    

Resolution  Asterisk now performs checks against manager commands that    
            cause these behaviors for each of the affected actions.       

                           Affected Versions
             Product               Release Series  
      Asterisk Open Source            1.6.2.x      All versions           
      Asterisk Open Source             1.8.x       All versions           
      Asterisk Open Source              10.x       All versions           
    Asterisk Business Edition          C.3.x       All versions           

                              Corrected In
              Product                              Release                
       Asterisk Open Source              1.6.2.24, 1.8.11.1, 10.3.1       
     Asterisk Business Edition                     C.3.7.4                

                                 Patches                          
                            SVN URL                               Revision 

http://downloads.asterisk.org/pub/security/AST-2012-004-1.6.2.diff v1.6.2
http://downloads.asterisk.org/pub/security/AST-2012-004-1.8.diff v1.8
http://downloads.asterisk.org/pub/security/AST-2012-004-10.diff v10

   Links     https://issues.asterisk.org/jira/browse/ASTERISK-17465       

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-2012-004.pdf and             
http://downloads.digium.com/pub/security/AST-2012-004.html                

                            Revision History
      Date                  Editor                 Revisions Made         
04/23/2012               Jonathan Rose             Initial Release              

           Asterisk Project Security Advisory - AST-2012-004
          Copyright (c) 2012 Digium, Inc. All Rights Reserved.

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