Directory traversal vulnerability in the get_category_template function in wp-includes/theme.php in WordPress 2.3.3 and earlier, and 2.5, allows remote attackers to include and possibly execute arbitrary PHP files via the cat parameter in index.php. NOTE: some of these details are obtained from third party information.
https://exchange.xforce.ibmcloud.com/vulnerabilities/41920
http://www.juniper.fi/security/auto/vulnerabilities/vuln28845.html
http://www.debian.org/security/2009/dsa-1871