vBulletin 5.4.3 has an Open Redirect.

vBulletin 3.x.x and 4.2.x through 4.2.5 has an open redirect via the redirector.php url parameter.

In vBulletin through 5.3.x, there is an unauthenticated deserialization vulnerability that leads to arbitrary file deletion and, under certain circumstances, code execution, because of unsafe usage of PHP's unserialize() in vB_Library_Template's cacheTemplates() function, which is a publicly exposed API. This is exploited with the templateidlist parameter to ajax/api/template/cacheTemplates.

vBulletin through 5.3.x on Windows allows remote PHP code execution because a require_once call is reachable with an unauthenticated request that can include directory traversal sequences to specify an arbitrary pathname, and because ../ traversal is blocked but ..\ traversal is not blocked. For example, an attacker can make an invalid HTTP request containing PHP code, and then make an index.php?routestring= request with enough instances of ".." to reach an Apache HTTP Server log file.

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.

Cross-site scripting (XSS) vulnerability in vBulletin 3.5.4, 3.6.0, 3.6.7, 3.8.7, 4.2.2, 5.0.5, and 5.1.3.

In vBulletin before 5.3.0, remote attackers can bypass the CVE-2016-6483 patch and conduct SSRF attacks by leveraging the behavior of the PHP parse_url function, aka VBV-17037.

The media-file upload feature in vBulletin before 3.8.7 Patch Level 6, 3.8.8 before Patch Level 2, 3.8.9 before Patch Level 1, 4.x before 4.2.2 Patch Level 6, 4.2.3 before Patch Level 2, 5.x before 5.2.0 Patch Level 3, 5.2.1 before Patch Level 1, and 5.2.2 before Patch Level 1 allows remote attackers to conduct SSRF attacks via a crafted URL that results in a Redirection HTTP status code.

SQL injection vulnerability in forumrunner/includes/moderation.php in vBulletin before 4.2.2 Patch Level 5 and 4.2.3 before Patch Level 1 allows remote attackers to execute arbitrary SQL commands via the postids parameter to forumrunner/request.php, as exploited in the wild in July 2016.

The vB_Api_Hook::decodeArguments method in vBulletin 5 Connect 5.1.2 through 5.1.9 allows remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via a crafted serialized object in the arguments parameter to ajax/api/hook/decodeArguments.