CVE-2013-3735: PHP

High severity, CVSS 7.5. EPSS: 2.8% chance of exploitation in the next 30 days.

The Zend Engine in PHP before 5.4.16 RC1, and 5.5.0 before RC2, does not properly determine whether a parser error occurred, which allows context-dependent attackers to cause a denial of service (memory consumption and application crash) via a crafted function definition, as demonstrated by an attack within a shared web-hosting environment. NOTE: the vendor's http://php.net/security-note.php page says "for critical security situations you should be using OS-level security by running multiple web servers each as their own user id.

Affected products

• PHP PHP: up to and including 5.4.15; version 5.4.0 only; version 5.4.1 only; version 5.4.2 only; version 5.4.3 only; version 5.4.4 only; …

Published 2013-05-31. Last modified 2026-06-16.