CVE-2005-3374: Frisk Software F-Prot Antivirus

Medium severity, CVSS 5.1. EPSS: 1.4% chance of exploitation in the next 30 days.

Multiple interpretation error in F-Prot 3.16c allows remote attackers to bypass virus scanning via a file such as BAT, HTML, and EML with an "MZ" magic byte sequence which is normally associated with EXE, which causes the file to be treated as a safe type that could still be executed as a dangerous file type by applications on the end system, as demonstrated by a "triple headed" program that contains EXE, EML, and HTML content, aka the "magic byte bug."

Affected products

Published 2005-10-30. Last modified 2026-06-16.