Listen and peer port validation in wg.inc
The listen port in function wg_validate_post and the peer port in function wg_validate_peer do not appear to be validated correctly. Just about any text can be entered and accepted. This could be an issue with form field validation elsewhere, but something along the lines of the following code might help....
if (empty($lport) || !ctype_digit ($lport) || !in_array ((int) $lport, range (0, 65535)))