hfaxd in HylaFAX before 4.2.1, when installed with a "weak" hosts.hfaxd file, allows remote attackers to authenticate and bypass intended access restrictions via a crafted (1) username or (2) hostname that satisfies a regular expression that is matched against a hosts.hfaxd entry without a password.
Buffer overflow in HylaFAX faxgetty before 4.1.3 allows remote attackers to cause a denial of service, and possibly execute arbitrary code, via a long line of image data.