[asterisk-bugs] [Asterisk 0017276]: [patch] bypass "contactdeny" with nat=yes

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
====================================================================== 
https://issues.asterisk.org/view.php?id=17276 
====================================================================== 
Reported By:                klaus3000
Assigned To:                twilson
====================================================================== 
Project:                    Asterisk
Issue ID:                   17276
Category:                   Channels/chan_sip/Registration
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     closed
Asterisk Version:           SVN 
JIRA:                       SWP-1462 
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases):  trunk 
SVN Revision (number only!):  
Request Review:              
Resolution:                 fixed
Fixed in Version:           
====================================================================== 
Date Submitted:             2010-05-03 09:56 CDT
Last Modified:              2010-07-16 12:34 CDT
====================================================================== 
Summary:                    [patch] bypass "contactdeny" with nat=yes
Description: 
Hi!

chan_sip's "contactdeny" feature screens the "to be registered contact".
In case of nat=yes it should not use the address information from the
Contact header (which is not used at all for routing), but the source IP
address of the request.

Thus, if nat=yes and a client sends a request from a denied IP address
(e.g. by spoofing the src-IP address) it can bypass the screening.
====================================================================== 

---------------------------------------------------------------------- 
 (0124622) svnbot (reporter) - 2010-07-16 12:34
 https://issues.asterisk.org/view.php?id=17276#c124622 
---------------------------------------------------------------------- 
Repository: asterisk
Revision: 270658

U   trunk/channels/chan_sip.c

------------------------------------------------------------------------
r270658 | twilson | 2010-06-15 15:18:04 -0500 (Tue, 15 Jun 2010) | 18
lines

Make contactdeny apply to src ip when nat=yes

chan_sip's "contactdeny" feature screens the "to be registered contact".
In case of nat=yes it should not use the address information from the
Contact header (which is not used at all for routing), but the source
IP address of the request.

Thus, if nat=yes and a client sends a request from a denied IP address
(e.g. by spoofing the src-IP address) it can bypass the screening.

This commit makes contactdeny apply to the src ip when nat=yes instead.

(closes issue https://issues.asterisk.org/view.php?id=17276)
Reported by: klaus3000
Patches: 
      patch-asterisk-trunk-contactdeny.txt uploaded by klaus3000 (license
65)
Tested by: klaus3000

------------------------------------------------------------------------

http://svn.digium.com/view/asterisk?view=rev&revision=270658 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2010-07-16 12:34 svnbot         Checkin                                      
2010-07-16 12:34 svnbot         Note Added: 0124622                          
======================================================================