Phorum 3.3.2a allows remote attackers to execute arbitrary commands via an HTTP request to (1) plugin.php, (2) admin.php, or (3) del.php that modifies the PHORUM[settings_dir] variable to point to a directory that contains a PHP file with the commands.
Exploitability
AV:NAC:LAu:NImpact
C:PI:PA:P7.5/AV:N/AC:L/Au:N/C:P/I:P/A:P