CVE-2000-0453: XFREE86 Project x11r6

Medium severity, CVSS 5.0. EPSS: 3% chance of exploitation in the next 30 days.

XFree86 3.3.x and 4.0 allows a user to cause a denial of service via a negative counter value in a malformed TCP packet that is sent to port 6000.

Affected products

• XFREE86 Project x11r6: version 3.3.5 only; version 3.3.6 only; version 4.0 only

Published 2000-05-18. Last modified 2026-06-16.