SQL injection vulnerability in vBulletin 5.0.4 through 5.1.3 Alpha 5 allows remote attackers to execute arbitrary SQL commands via the criteria[startswith] parameter to ajax/render/memberlistitems.
Cross-site scripting (XSS) vulnerability in admincp/apilog.php in vBulletin 4.2.2 and earlier, and 5.0.x through 5.0.5 allows remote authenticated users to inject arbitrary web script or HTML via a crafted XMLRPC API request, as demonstrated using the client name.
vBulletin 5.x through 5.1.6 allows remote authenticated users to bypass authorization checks and inject private messages into conversations via vectors related to an input validation failure.