FormMail CGI program can be used by web servers other than the host server that the program resides on.
CRLF injection vulnerability in FormMail.pl in Matt Wright FormMail 1.92, and possibly earlier, allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via the redirect parameter.
Matt Wright FormMail 1.9 and earlier allows remote attackers to send spam or anonymous e-mail by injecting a newline character followed by CC:, BCC:, or additional TO: fields in the email and realname CGI variables.