PHP is an HTML-embedded scripting language commonly used with the Apache HTTP Server.
A memory corruption flaw was found in the way the openssl_x509_parse() function of the PHP openssl extension parsed X.509 certificates. A remote attacker could use this flaw to provide a malicious self-signed certificate or a certificate signed by a trusted authority to a PHP application using the aforementioned function, causing the application to crash or, possibly, allow the attacker to execute arbitrary code with the privileges of the user running the PHP interpreter. (CVE-2013-6420)
Red Hat would like to thank the PHP project for reporting this issue. Upstream acknowledges Stefan Esser as the original reporter of this issue.
All php users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. After installing the updated packages, the httpd daemon must be restarted for the update to take effect.