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.
PHP makes use of a private copy of libpcre which is subject to an integer overflow leading to a heap overflow (see GLSA 200508-17). It also ships with an XML-RPC library affected by a script injection vulnerability (see GLSA 200508-13).
An attacker could target a PHP-based web application that would use untrusted data as regular expressions, potentially resulting in the execution of arbitrary code. If web applications make use of the XML-RPC library shipped with PHP, they are also vulnerable to remote execution of arbitrary PHP code.
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
All mod_php users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose dev-php/mod_php
All php-cgi users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose dev-php/php-cgi