CVE-2002-0964: Valve Software Half-Life

Medium severity, CVSS 5.0. EPSS: 3.2% chance of exploitation in the next 30 days.

Half-Life Server 1.1.1.0 and earlier allows remote attackers to cause a denial of service (resource exhaustion) via multiple responses to the initial challenge with different cd_key values, which reaches the player limit and prevents other players from connecting until the original responses have timed out.

Affected products

• Valve Software Half-Life: version 1.1.0.4 only; version 1.1.0.8 only; version 1.1.0.9 only; version 1.1.1.0 only
• Valve Software Half-Life Dedicated Server: up to and including 3.1; version 3.1.3 only

Published 2002-10-04. Last modified 2026-06-16.