(RHSA-2011:1391) Moderate: httpd security and bug fix update

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.