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.
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 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.
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/memberlist_items.
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.