[asterisk-security] AST-2022-002: res_stir_shaken: SSRF vulnerability with Identity header

[Asterisk Security Team]

               Asterisk Project Security Advisory - AST-2022-002

         Product        Asterisk                                              
         Summary        res_stir_shaken: SSRF vulnerability with Identity     
                        header                                                
    Nature of Advisory  Server-side request forgery                           
      Susceptibility    Remote unauthenticated access                         
         Severity       Major                                                 
      Exploits Known    No                                                    
       Reported On      Jun 10, 2021                                          
       Reported By      Clint Ruoho                                           
        Posted On       Apr 14, 2022                                          
     Last Updated On    April 13, 2022                                        
     Advisory Contact   bford AT sangoma DOT com                              
         CVE Name       CVE-2022-26499                                        

      Description     When using STIR/SHAKEN, it’s possible to send           
                      arbitrary requests like GET to interfaces such as       
                      localhost using the Identity header.                    
    Modules Affected  res_stir_shaken                                         

    Resolution  If you are using STIR/SHAKEN in Asterisk, upgrade to one of   
                the versions listed below to get a new configuration option:  
                stir_shaken_profile. This can be configured in                
                stir_shaken.conf and set on a per endpoint basis in           
                pjsip.conf. This option will take priority over the           
                stir_shaken option. The stir_shaken_profile will contain the  
                stir_shaken option (attest, verify, or both), as well as ACL  
                configuration options to permit and deny specific IP          
                addresses / hosts. The ACL will be used for the public key    
                URL we receive in the Identity header, which is used to tell  
                Asterisk where to download the public certificate. An ACL     
                from acl.conf can be used, but you can specify your own       
                permit and deny lines within the profile itself. A            
                combination of both can also be used.                         
                                                                              
                Note that this patch contains changes that affect the same    
                area as the patch from AST-2022-001. It is recommended that   
                you upgrade to a listed version, otherwise you might          
                encounter merge conflicts.                                    

                               Affected Versions
               Product             Release Series  
        Asterisk Open Source            16.x       16.15.0 and after          
        Asterisk Open Source            18.x       All versions               
        Asterisk Open Source            19.x       All versions               

                                  Corrected In
                 Product                              Release                 
          Asterisk Open Source               16.25.2, 18.11.2, 19.3.2         

                                    Patches                         
                              Patch URL                             Revision  
    https://downloads.digium.com/pub/security/AST-2022-002-16.diff  Asterisk  
                                                                    16        
    https://downloads.digium.com/pub/security/AST-2022-002-18.diff  Asterisk  
                                                                    18        
    https://downloads.digium.com/pub/security/AST-2022-002-19.diff  Asterisk  
                                                                    19        

     Links   https://issues.asterisk.org/jira/browse/ASTERISK-29476           
                                                                              
             https://downloads.asterisk.org/pub/security/AST-2022-002.html    

    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                                                 
    https://downloads.digium.com/pub/security/AST-2022-002.pdf and            
    https://downloads.digium.com/pub/security/AST-2022-002.html               

                                Revision History
          Date                 Editor                 Revisions Made          
    Apr 13, 2022       Ben Ford                Initial revision               

               Asterisk Project Security Advisory - AST-2022-002
            Copyright © 01/19/2022 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.