CVE-2009-3558: PHP

Medium severity, CVSS 6.8. EPSS: 2.1% chance of exploitation in the next 30 days.

The posix_mkfifo function in ext/posix/posix.c in PHP before 5.2.12 and 5.3.x before 5.3.1 allows context-dependent attackers to bypass open_basedir restrictions, and create FIFO files, via the pathname and mode arguments, as demonstrated by creating a .htaccess file.

Affected products

• PHP PHP: up to and including 5.2.10; version 1.0 only; version 2.0 only; version 2.0b10 only; version 3.0 only; version 3.0.1 only; …

Published 2009-11-23. Last modified 2026-06-16.