Synopsis

Moderate: httpd security and bug fix update

Type/Severity

Security Advisory: Moderate

Topic

Updated httpd packages that fix two security issues and one bug are now
available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate
security impact. Common Vulnerability Scoring System (CVSS) base scores,
which give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.

Description

The Apache HTTP Server is a popular web server.

It was discovered that the Apache HTTP Server did not properly validate the
request URI for proxied requests. In certain configurations, if a reverse
proxy used the ProxyPassMatch directive, or if it used the RewriteRule
directive with the proxy flag, a remote attacker could make the proxy
connect to an arbitrary server, possibly disclosing sensitive information
from internal web servers not directly accessible to the attacker.
(CVE-2011-3368)

It was discovered that mod_proxy_ajp incorrectly returned an "Internal
Server Error" response when processing certain malformed HTTP requests,
which caused the back-end server to be marked as failed in configurations
where mod_proxy was used in load balancer mode. A remote attacker could
cause mod_proxy to not send requests to back-end AJP (Apache JServ
Protocol) servers for the retry timeout period or until all back-end
servers were marked as failed. (CVE-2011-3348)

Red Hat would like to thank Context Information Security for reporting the
CVE-2011-3368 issue.

This update also fixes the following bug:

• The fix for CVE-2011-3192 provided by the RHSA-2011:1245 update

introduced regressions in the way httpd handled certain Range HTTP header
values. This update corrects those regressions. (BZ#736592)

All httpd users should upgrade to these updated packages, which contain
backported patches to correct these issues. After installing the updated
packages, the httpd daemon must be restarted for the update to take effect.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.1 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.1 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.1 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.1 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.1 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.1 i386
• Red Hat Virtual Storage Appliance (from RHUI) 6.1 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 736592 - httpd: RHSA-2011:1245 regressions [rhel-6]
• BZ - 736690 - CVE-2011-3348 httpd: mod_proxy_ajp remote temporary DoS
• BZ - 740045 - CVE-2011-3368 httpd: reverse web proxy vulnerability

CVEs

• CVE-2011-3368
• CVE-2011-3348

References