PHP is a general-purpose scripting language widely used to develop web-based applications. It can run inside a web server using the mod_php module or the CGI version of PHP, or can run stand-alone in a CLI.
James Bercegay has discovered that the XML-RPC implementation in PHP fails to sanitize input passed in an XML document, which is used in an "eval()" statement.
A remote attacker could exploit the XML-RPC vulnerability to execute arbitrary PHP script code by sending specially crafted XML data to applications making use of this XML-RPC implementation.
There is no known workaround at this time.
All PHP users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-php/php-4.4.0"