(RHSA-2008:0546) Moderate: php security update

PHP is an HTML-embedded scripting language commonly used with the Apache
HTTP Web server.

It was discovered that the PHP escapeshellcmd() function did not properly
escape multi-byte characters which are not valid in the locale used by the
script. This could allow an attacker to bypass quoting restrictions imposed
by escapeshellcmd() and execute arbitrary commands if the PHP script was
using certain locales. Scripts using the default UTF-8 locale are not
affected by this issue. (CVE-2008-2051)

The PHP functions htmlentities() and htmlspecialchars() did not properly
recognize partial multi-byte sequences. Certain sequences of bytes could be
passed through these functions without being correctly HTML-escaped.
Depending on the browser being used, an attacker could use this flaw to
conduct cross-site scripting attacks. (CVE-2007-5898)

A PHP script which used the transparent session ID configuration option, or
which used the output_add_rewrite_var() function, could leak session
identifiers to external web sites. If a page included an HTML form with an
ACTION attribute referencing a non-local URL, the user’s session ID would
be included in the form data passed to that URL. (CVE-2007-5899)

It was discovered that PHP did not properly seed its pseudo-random number
generator used by functions such as rand() and mt_rand(), possibly allowing
an attacker to easily predict the generated pseudo-random values.
(CVE-2008-2107, CVE-2008-2108)

Integer overflow and memory requirements miscalculation issues were
discovered in the Perl-Compatible Regular Expression (PCRE) library used by
PHP to process regular expressions. These issues could cause a crash, or
possibly execute an arbitrary code with the privileges of the PHP script
that processes regular expressions from untrusted sources. Note: PHP
packages shipped with Red Hat Enterprise Linux 2.1 did not use the
system-level PCRE library. By default they used an embedded copy of the
library included with the PHP package. (CVE-2006-7228, CVE-2007-1660)

Users of PHP should upgrade to these updated packages, which contain
backported patches to correct these issues.