Matt Wright FormMail 1.9 and earlier allows remote attackers to bypass the HTTP_REFERER check and conduct unauthorized activities via (1) a blank referer, (2) a spoofed referer with a trusted domain/URL after the beginning of the referer, or (3) a spoofed referer with a trusted domain/URL in the beginning (hostname) portion of the referer.
Exploitability
AV:NAC:LAu:NImpact
C:PI:PA:P7.5/AV:N/AC:L/Au:N/C:P/I:P/A:P