SEPPmail Secure Email Gateway before version 15.0.3 allows attackers with a specially crafted email address to claim another user's PGP signature as their own.
SEPPmail Secure Email Gateway before version 15.0.1 incorrectly interprets email addresses in the email headers, causing an interpretation conflict with other mail infrastructure that allows an attacker to fake the source of the email or decrypt it.
SEPPmail Secure Email Gateway before version 15.0.1 does not properly sanitize the headers from S/MIME protected MIME entities, allowing an attacker to control trusted headers.