CVE-2004-0371: Heimdal 0.6.x before 0.6.1 and 0.5.x before 0.5.3 does not properly perform certain consistency checks for...

Security readout for executives and security teams

This is an old Heimdal Kerberos flaw affecting 0.6.x before 0.6.1 and 0.5.x before 0.5.3. If an attacker controls a trusted Kerberos realm, they may impersonate identities across the cross-realm trust path. Business risk is highest where legacy Heimdal still supports inter-realm authentication. Likely limited to legacy systems running vulnerable Heimdal versions and using Kerberos cross-realm trust. Modern environments are exposed only if old packages, appliances, or embedded systems remain unpatched. Prioritize if the organization still operates legacy Heimdal Kerberos or cross-realm authentication. For fully patched modern Kerberos deployments, urgency is lower, but legacy identity infrastructure should be audited. Mitigation focus: Upgrade Heimdal to 0.6.1, 0.5.3, or later where applicable.; Apply relevant vendor OS security updates from affected distributions.; Review and reduce unnecessary Kerberos cross-realm trust relationships..

Prepared

Jul 12, 2026, 01:15 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.