phpMyAdmin before 2.9.1.1 allows remote attackers to bypass Allow/Deny access rules that use IP addresses via false headers.
http://www.vupen.com/english/advisories/2006/4572
http://www.us.debian.org/security/2007/dsa-1370
http://www.phpmyadmin.net/home_page/security.php?issue=PMASA-2006-9