Moderate: php security update
Security Advisory: Moderate
Updated php packages that fix several security issues are now available for
Red Hat Enterprise Linux 3, 4, and 5.
This update has been rated as having moderate security impact by the Red
Hat Security Response Team.
PHP is an HTML-embedded scripting language commonly used with the Apache
HTTP Web server.
Multiple missing input sanitization flaws were discovered in PHP's exif
extension. A specially-crafted image file could cause the PHP interpreter
to crash or, possibly, disclose portions of its memory when a PHP script
tried to extract Exchangeable image file format (Exif) metadata from the
image file. (CVE-2009-2687, CVE-2009-3292)
A missing input sanitization flaw, leading to a buffer overflow, was
discovered in PHP's gd library. A specially-crafted GD image file could
cause the PHP interpreter to crash or, possibly, execute arbitrary code
when opened. (CVE-2009-3546)
It was discovered that PHP did not limit the maximum number of files that
can be uploaded in one request. A remote attacker could use this flaw to
instigate a denial of service by causing the PHP interpreter to use lots of
system resources dealing with requests containing large amounts of files to
be uploaded. This vulnerability depends on file uploads being enabled
(which it is, in the default PHP configuration). (CVE-2009-4017)
Note: This update introduces a new configuration option, max_file_uploads,
used for limiting the number of files that can be uploaded in one request.
By default, the limit is 20 files per request.
It was discovered that PHP was affected by the previously published "null
prefix attack", caused by incorrect handling of NUL characters in X.509
certificates. If an attacker is able to get a carefully-crafted certificate
signed by a trusted Certificate Authority, the attacker could use the
certificate during a man-in-the-middle attack and potentially confuse PHP
into accepting it by mistake. (CVE-2009-3291)
It was discovered that PHP's htmlspecialchars() function did not properly
recognize partial multi-byte sequences for some multi-byte encodings,
sending them to output without them being escaped. An attacker could use
this flaw to perform a cross-site scripting attack. (CVE-2009-4142)
All php users should upgrade to these updated packages, which contain
backported patches to resolve these issues. After installing the updated
packages, the httpd daemon must be restarted for the update to take effect.
Before applying this update, make sure that all previously-released
errata relevant to your system have been applied.
This update is available via 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
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