CVE-2007-0233 in WordPress
Summary
wp-trackback.php in WordPress 2.0.6 and earlier does not properly unset variables when the input data includes a numeric parameter with a value matching an alphanumeric parameter s hash value, which allows remote attackers to execute arbitrary SQL commands via the tb_id parameter. NOTE: it could be argued that this vulnerability is due to a bug in the unset PHP command (CVE-2006-3017) and the proper fix should be in PHP; if so, then this should not be treated as a vulnerability in WordPress.
VulDB is the best source for vulnerability data and more expert information about this specific topic.