AST-2015-003: TLS Certificate Common name NULL byte exploit

2015-04-1300:00:00

vulners.com

           Asterisk Project Security Advisory - AST-2015-003

     Product        Asterisk                                              
     Summary        TLS Certificate Common name NULL byte exploit         
Nature of Advisory  Man in the Middle Attack                              
  Susceptibility    Remote Authenticated Sessions                         
     Severity       Major                                                 
  Exploits Known    None                                                  
   Reported On      12 January, 2015                                      
   Reported By      Maciej Szmigiero                                      
    Posted On       March 04, 2015                                        
 Last Updated On    April 8, 2015                                         
 Advisory Contact   Jonathan Rose &lt;jrose AT digium DOT com&gt;               
     CVE Name       CVE-2015-3008

Description When Asterisk registers to a SIP TLS device and and verifies the
server, Asterisk will accept signed certificates that match a
common name other than the one Asterisk is expecting if the
signed certificate has a common name containing a null byte
after the portion of the common name that Asterisk expected. For
example, if Asterisk is trying to register to www.domain.com,
Asterisk will accept certificates of the form
www.domain.com\x00www.someotherdomain.com - for more information
on this exploit, see
https://fotisl.com/blog/2009/10/the-null-certificate-prefix-bug/

Resolution  Asterisk has been patched to verify that the common name      
            length of the certificate matches the common name that        
            Asterisk actually reads. Asterisk will not accept             
            certificates with common names that contain null bytes.       

                           Affected Versions       
                     Product                       Release  
                                                   Series   
              Asterisk Open Source                  1.8.x   All versions  
              Asterisk Open Source                  11.x    All versions  
              Asterisk Open Source                  12.x    All versions  
              Asterisk Open Source                  13.x    All versions  
               Certified Asterisk                  1.8.28   All versions  
               Certified Asterisk                   11.6    All versions  
               Certified Asterisk                   13.1    All versions  

                              Corrected In
      Product                              Release                        
Asterisk Open Source           1.8.32.3, 11.17.1, 12.8.2 13.3.2           
 Certified Asterisk         1.8.28-cert5, 11.6-cert11, 13.1-cert2         

                                  Patches                          
                             SVN URL                               Revision

http://downloads.asterisk.org/pub/security/AST-2015-003-1.8.28.diff Certified
Asterisk
1.8.28
http://downloads.asterisk.org/pub/security/AST-2015-003-11.6.diff Certified
Asterisk
11.6
http://downloads.asterisk.org/pub/security/AST-2015-003-13.1.diff Certified
Asterisk
13.1
http://downloads.asterisk.org/pub/security/AST-2015-003-1.8.diff Asterisk
1.8
http://downloads.asterisk.org/pub/security/AST-2015-003-11.diff Asterisk
11
http://downloads.asterisk.org/pub/security/AST-2015-003-12.diff Asterisk
12
http://downloads.asterisk.org/pub/security/AST-2015-003-13.diff Asterisk
13

Links  https://issues.asterisk.org/jira/browse/ASTERISK-24847             

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-2015-003.pdf and             
http://downloads.digium.com/pub/security/AST-2015-003.html                

                            Revision History
     Date          Editor                   Revisions Made                
19 March, 2015  Jonathan Rose  Initial creation of document               
08 April, 2015  Matt Jordan    Added CVE.                                 

           Asterisk Project Security Advisory - AST-2015-003
          Copyright &#40;c&#41; 2015 Digium, Inc. All Rights Reserved.

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