Allaire Forums 2.0.4 and 2.0.5 and Forums! 3.0 and 3.1 allows remote authenticated users to spoof messages as other users by modifying the hidden form fields for the name and e-mail address.
Exploitability
AV:NAC:LAu:NImpact
C:PI:PA:P7.5/AV:N/AC:L/Au:N/C:P/I:P/A:P