Red Hat Enterprise Linux 2.1 RHSA-2008:0546-01 Moderate: PHP Script Flaws

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.