Bug 1016832 (CVE-2013-4566) - CVE-2013-4566 mod_nss: incorrect handling of NSSVerifyClient in directory context
Summary: CVE-2013-4566 mod_nss: incorrect handling of NSSVerifyClient in directory con...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2013-4566
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 989724 1024536 1030264 1030265 1030267 1030268 1030270 1037722 1037761
Blocks: 830846
TreeView+ depends on / blocked
 
Reported: 2013-10-08 19:07 UTC by Tomas Hoger
Modified: 2021-02-17 07:18 UTC (History)
13 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2013-12-13 09:55:47 UTC

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System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2013:1779 0 normal SHIPPED_LIVE Moderate: mod_nss security update 2013-12-03 21:39:53 UTC

Description Tomas Hoger 2013-10-08 19:07:42 UTC 
A flaw was found in the way NSSVerifyClient was handled when used in both server / vhost context as well as directory context (specified either via <Directory> or <Location> directive).  If 'NSSVerifyClient none' was set in the server / vhost context (i.e. when server is configured to not request or require client certificate authentication on the initial connection), and client certificate authentication was expected to be required for a specific directory via 'NSSVerifyClient require' setting, mod_nss failed to properly require expected certificate authentication.  Remote attacker able to connect to the web server using such mod_nss configuration and without a valid client certificate could possibly use this flaw to access content of the restricted directories.

Documentation of mod_nss configuration directives, including NSSVerifyClient:

https://git.fedorahosted.org/cgit/mod_nss.git/plain/docs/mod_nss.html#Directives

As mod_nss is derived form mod_ssl, NSSVerifyClient is meant to be functionally equivalent to mod_ssl's SSLVerifyClient:

http://httpd.apache.org/docs/2.2/mod/mod_ssl.html#sslverifyclient
Comment 7 Tomas Hoger 2013-11-19 16:29:56 UTC 
Acknowledgment:

Red Hat would like to thank Albert Smith of OUSD(AT&L) for reporting this issue.
Comment 9 Vincent Danen 2013-12-03 16:32:22 UTC 
Created mod_nss tracking bugs for this issue:

Affects: fedora-all [bug 1037722]
Comment 10 errata-xmlrpc 2013-12-03 16:41:05 UTC 
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5
  Red Hat Enterprise Linux 6

Via RHSA-2013:1779 https://rhn.redhat.com/errata/RHSA-2013-1779.html
Comment 11 Tomas Hoger 2013-12-04 19:43:15 UTC 
Patch as applied to Fedora mod_nss packages:

http://pkgs.fedoraproject.org/cgit/mod_nss.git/tree/mod_nss-nssverifyclient.patch?id=63709b8

Not yet merged in mod_nss upstream repository.
Comment 12 Fedora Update System 2013-12-13 05:03:51 UTC 
mod_nss-1.0.8-27.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 13 Fedora Update System 2013-12-13 05:04:57 UTC 
mod_nss-1.0.8-27.fc18 has been pushed to the Fedora 18 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 14 Fedora Update System 2013-12-14 03:03:25 UTC 
mod_nss-1.0.8-28.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.
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