functions_vbseo_hook.php in the VBSEO module for vBulletin allows remote authenticated users to execute arbitrary code via the HTTP Referer header to visitormessage.php.
Directory traversal vulnerability in vbseo.php in Crawlability vBSEO plugin 3.1.0 for vBulletin allows remote attackers to include and execute arbitrary local files via directory traversal sequences in the vbseourl parameter.