9.3 - RHSA-2010:0040

Problem Description:

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.

2. Relevant releases/architectures:

RHEL Desktop Workstation (v. 5 client) - i386, x86_64 Red Hat Desktop version 3 - i386, x86_64 Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64 Red Hat Enterprise Linux AS version 3 - i386, ia64, ppc, s390, s390x, x86_64 Red Hat Enterprise Linux AS version 4 - i386, ia64, ppc, s390, s390x, x86_64 Red Hat Enterprise Linux Desktop version 4 - i386, x86_64 Red Hat Enterprise Linux ES version 3 - i386, ia64, x86_64 Red Hat Enterprise Linux ES version 4 - i386, ia64, x86_64 Red Hat Enterprise Linux WS version 3 - i386, ia64, x86_64 Red Hat Enterprise Linux WS version 4 - i386, ia64, x86_64

3. Description:

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.

4. Solution:

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

5. Bugs fixed (http://bugzilla.redhat.com/):

506896 - CVE-2009-2687 php: exif_read_data crash on corrupted JPEG files 524222 - CVE-2009-3292 php: exif extension: Multiple missing sanity checks in EXIF file processing 524228 - CVE-2009-3291 php: openssl extension: Incorrect verification of SSL certificate with NUL in name 529213 - CVE-2009-3546 gd: insufficient input validation in _gdGetColors() 540459 - CVE-2009-4017 PHP: resource exhaustion attack via upload requests with lots of files 548516 - CVE-2009-4142 php: htmlspecialchars() insufficient checking of input for multi-byte encodings