RHSA-2015:0325 - Security Advisory

Topic

Updated httpd packages that fix two security issues, several bugs, and add
various enhancements are for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having Low 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 httpd packages provide the Apache HTTP Server, a powerful, efficient, and
extensible web server.

A flaw was found in the way httpd handled HTTP Trailer headers when processing
requests using chunked encoding. A malicious client could use Trailer headers to
set additional HTTP headers after header processing was performed by other
modules. This could, for example, lead to a bypass of header restrictions
defined with mod_headers. (CVE-2013-5704)

A NULL pointer dereference flaw was found in the way the mod_cache httpd module
handled Content-Type headers. A malicious HTTP server could cause the httpd
child process to crash when the Apache HTTP server was configured to proxy to a
server with caching enabled. (CVE-2014-3581)

This update also fixes the following bugs:

• Previously, the mod_proxy_fcgi Apache module always kept the back-end

connections open even when they should have been closed. As a consequence, the
number of open file descriptors was increasing over the time. With this update,
mod_proxy_fcgi has been fixed to check the state of the back-end connections,
and it closes the idle back-end connections as expected. (BZ#1168050)

• An integer overflow occurred in the ab utility when a large request count was

used. Consequently, ab terminated unexpectedly with a segmentation fault while
printing statistics after the benchmark. This bug has been fixed, and ab no
longer crashes in this scenario. (BZ#1092420)

• Previously, when httpd was running in the foreground and the user pressed

Ctrl+C to interrupt the httpd processes, a race condition in signal handling
occurred. The SIGINT signal was sent to all children followed by SIGTERM from
the main process, which interrupted the SIGINT handler. Consequently, the
affected processes became unresponsive or terminated unexpectedly. With this
update, the SIGINT signals in the child processes are ignored, and httpd no
longer hangs or crashes in this scenario. (BZ#1131006)

In addition, this update adds the following enhancements:

• With this update, the mod_proxy module of the Apache HTTP Server supports the

Unix Domain Sockets (UDS). This allows mod_proxy back ends to listen on UDS
sockets instead of TCP sockets, and as a result, mod_proxy can be used to
connect UDS back ends. (BZ#1168081)

• This update adds support for using the SetHandler directive together with the

mod_proxy module. As a result, it is possible to configure SetHandler to use
proxy for incoming requests, for example, in the following format: SetHandler
"proxy:fcgi://127.0.0.1:9000". (BZ#1136290)

• The htaccess API changes introduced in httpd 2.4.7 have been backported to

httpd shipped with Red Hat Enterprise Linux 7.1. These changes allow for the
MPM-ITK module to be compiled as an httpd module. (BZ#1059143)

All httpd users are advised to upgrade to these updated packages, which contain
backported patches to correct these issues and add these enhancements. After
installing the updated packages, the httpd daemon will be restarted
automatically.

Solution

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

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.3 x86_64

Fixes

• BZ - 1059143 - Feature request: update httpd to 2.4.7 / backport htaccess API changes
• BZ - 1060536 - mod_rewrite doesn't expose client_addr
• BZ - 1073078 - mod_ssl uses small DHE parameters for non standard RSA keys
• BZ - 1073081 - mod_ssl selects correct DHE parameters for keys only up to 4096 bit
• BZ - 1080125 - httpd uses hardcoded curve for ECDHE suites
• BZ - 1082903 - CVE-2013-5704 httpd: bypass of mod_headers rules via chunked requests
• BZ - 1114123 - RFE: set vstring dynamically
• BZ - 1131006 - Error in `/usr/sbin/httpd': free(): invalid pointer
• BZ - 1131847 - authzprovideralias and authnprovideralias-defined provider can't be used in virtualhost .
• BZ - 1136290 - SetHandler to proxy support
• BZ - 1149709 - CVE-2014-3581 httpd: NULL pointer dereference in mod_cache if Content-Type has empty value

CVEs

• CVE-2013-5704
• CVE-2014-3581

References

• https://access.redhat.com/security/updates/classification/#low