Cross-site scripting (XSS) vulnerability in memberlist.php in Jelsoft vBulletin 2.0 rc 2 through 2.2.4 allows remote attackers to steal authentication credentials by injecting script into $letterbits.

member2.php in vBulletin 2.2.9 and earlier does not properly restrict the $perpage variable to be an integer, which causes an error message to be reflected back to the user without quoting, which facilitates cross-site scripting (XSS) and possibly other attacks.

Cross-site scripting (XSS) vulnerability in global.php in Jelsoft vBulletin 2.0.0 through 2.2.8 allows remote attackers to inject arbitrary web script or HTML via the (1) $scriptpath or (2) $url variables.