Multiple cross-site scripting (XSS) vulnerabilities in (1) login.php, (2) register.php, (3) post.php, and (4) common.php in Phorum before 3.4.3 allow remote attackers to inject arbitrary web script or HTML via unknown attack vectors.
The ugidd RPC interface, by design, allows remote attackers to enumerate valid usernames by specifying arbitrary UIDs that ugidd maps to local user and group names.