CVE-2021-33600: F-Secure Internet Gatekeeper

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

A denial-of-service (DoS) vulnerability was discovered in the web user interface of F-Secure Internet Gatekeeper. The vulnerability occurs because of an attacker can trigger assertion via malformed HTTP packet to web interface. An unauthenticated attacker could exploit this vulnerability by sending a large username parameter. A successful exploitation could lead to a denial-of-service of the product.

Affected products

• F-Secure Internet Gatekeeper: from 5.10, up to and including 5.50.47

Published 2021-09-28. Last modified 2026-06-17.