USN-1259-1: Apache vulnerabilities

Ubuntu Security Notice USN-1259-1

10th November, 2011

apache2, apache2-mpm-itk vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 11.10
  • Ubuntu 11.04
  • Ubuntu 10.10
  • Ubuntu 10.04 LTS
  • Ubuntu 8.04 LTS


Multiple vulnerabilities and a regression were fixed in the Apache HTTP server.

Software description

  • apache2 - Apache HTTP server
  • apache2-mpm-itk - multiuser MPM for Apache


It was discovered that the mod_proxy module in Apache did not properly
interact with the RewriteRule and ProxyPassMatch pattern matches
in the configuration of a reverse proxy. This could allow remote
attackers to contact internal webservers behind the proxy that were
not intended for external exposure. (CVE-2011-3368)

Stefano Nichele discovered that the mod_proxy_ajp module in Apache when
used with mod_proxy_balancer in certain configurations could allow
remote attackers to cause a denial of service via a malformed HTTP
request. (CVE-2011-3348)

Samuel Montosa discovered that the ITK Multi-Processing Module for
Apache did not properly handle certain configuration sections that
specify NiceValue but not AssignUserID, preventing Apache from dropping
privileges correctly. This issue only affected Ubuntu 10.04 LTS, Ubuntu
10.10 and Ubuntu 11.04. (CVE-2011-1176)

USN 1199-1 fixed a vulnerability in the byterange filter of Apache. The
upstream patch introduced a regression in Apache when handling specific
byte range requests. This update fixes the issue.

Original advisory details:

A flaw was discovered in the byterange filter in Apache. A remote attacker
could exploit this to cause a denial of service via resource exhaustion.

Update instructions

The problem can be corrected by updating your system to the following package version:

Ubuntu 11.10:
apache2.2-bin 2.2.20-1ubuntu1.1
Ubuntu 11.04:
apache2-mpm-itk 2.2.17-1ubuntu1.4
apache2.2-bin 2.2.17-1ubuntu1.4
Ubuntu 10.10:
apache2-mpm-itk 2.2.16-1ubuntu3.4
apache2.2-bin 2.2.16-1ubuntu3.4
Ubuntu 10.04 LTS:
apache2-mpm-itk 2.2.14-5ubuntu8.7
apache2.2-bin 2.2.14-5ubuntu8.7
Ubuntu 8.04 LTS:
apache2.2-common 2.2.8-1ubuntu0.22

To update your system, please follow these instructions:

In general, a standard system update will make all the necessary changes.


CVE-2011-1176, CVE-2011-3348, CVE-2011-3368