RHSA-2012:0543 - Security Advisory
Moderate: httpd security and bug fix update
Security Advisory: Moderate
An update for the Apache HTTP Server component for JBoss Enterprise Web
Server 1.0.2 that fixes multiple security issues and one bug is now
available from the Red Hat Customer Portal.
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.
The Apache HTTP Server ("httpd") is the namesake project of The Apache
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.
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)
The httpd server included the full HTTP header line in the default error
page generated when receiving an excessively long or malformed header.
flaw to gain access to httpOnly cookies. (CVE-2012-0053)
An integer overflow flaw, leading to a heap-based buffer overflow, was
found in the way httpd performed substitutions in regular expressions. An
attacker able to set certain httpd settings, such as a user permitted to
override the httpd configuration for a specific directory using a
".htaccess" file, could use this flaw to crash the httpd child process or,
possibly, execute arbitrary code with the privileges of the "apache" user.
A NULL pointer dereference flaw was found in the httpd mod_log_config
module. In configurations where cookie logging is enabled, a remote
attacker could use this flaw to crash the httpd child process via an HTTP
request with a malformed Cookie header. (CVE-2012-0021)
A flaw was found in the way httpd handled child process status information.
A malicious program running with httpd child process privileges (such as a
PHP or CGI script) could use this flaw to cause the parent httpd process to
crash during httpd service shutdown. (CVE-2012-0031)
Red Hat would like to thank Context Information Security for reporting the
This update also fixes the following bug:
- The fix for CVE-2011-3192 provided by the RHSA-2011:1330 update
introduced a regression in the way httpd handled certain Range HTTP header
values. This update corrects this regression. (BZ#749071)
All users of JBoss Enterprise Web Server 1.0.2 as provided from the Red Hat
Customer Portal are advised to apply this update.
The References section of this erratum contains a download link (you must
log in to download the update). Before applying the update, back up your
existing JBoss Enterprise Web Server installation (including all
applications and configuration files).
The Apache HTTP Server must be restarted for this update to take effect.
- JBoss Enterprise Web Server Text-Only Advisories x86_64
- BZ - 736690 - CVE-2011-3348 httpd: mod_proxy_ajp remote temporary DoS
- BZ - 740045 - CVE-2011-3368 httpd: reverse web proxy vulnerability
- BZ - 769844 - CVE-2011-3607 httpd: ap_pregsub Integer overflow to buffer overflow
- BZ - 773744 - CVE-2012-0031 httpd: possible crash on shutdown due to flaw in scoreboard handling
- BZ - 785065 - CVE-2012-0021 httpd: NULL pointer dereference crash in mod_log_config
- BZ - 785069 - CVE-2012-0053 httpd: cookie exposure due to error responses
JBoss Enterprise Web Server Text-Only Advisories