RHSA-2010:0168 - Security Advisory

Topic

Updated httpd packages that fix two security issues and add an enhancement
are now available for Red Hat Enterprise Linux 5.

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 mod_proxy_ajp incorrectly returned an "Internal
Server Error" response when processing certain malformed requests, which
caused the back-end server to be marked as failed in configurations where
mod_proxy is 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 (60 seconds by default) by sending
specially-crafted requests. (CVE-2010-0408)

A use-after-free flaw was discovered in the way the Apache HTTP Server
handled request headers in subrequests. In configurations where subrequests
are used, a multithreaded MPM (Multi-Processing Module) could possibly leak
information from other requests in request replies. (CVE-2010-0434)

This update also adds the following enhancement:

• with the updated openssl packages from RHSA-2010:0162 installed, mod_ssl

will refuse to renegotiate a TLS/SSL connection with an unpatched client
that does not support RFC 5746. This update adds the
"SSLInsecureRenegotiation" configuration directive. If this directive is
enabled, mod_ssl will renegotiate insecurely with unpatched clients.
(BZ#567980)

Refer to the following Red Hat Knowledgebase article for more details about
the changed mod_ssl behavior: http://kbase.redhat.com/faq/docs/DOC-20491

All httpd users should upgrade to these updated packages, which contain
backported patches to correct these issues and add this enhancement. 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
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.4 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.4 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.4 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.4 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 567980 - [RFE] mod_ssl: Add SSLInsecureRenegotiation directive [rhel-5]
• BZ - 569905 - CVE-2010-0408 httpd: mod_proxy_ajp remote temporary DoS
• BZ - 570171 - CVE-2010-0434 httpd: request header information leak

CVEs

• CVE-2010-0408
• CVE-2010-0434

References

• http://www.redhat.com/security/updates/classification/#moderate
• http://kbase.redhat.com/faq/docs/DOC-20491