CVE-2018-6557: Base-Files Project Base-Files

High severity, CVSS 7.0. EPSS: 0.4% chance of exploitation in the next 30 days.

The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled.

Affected products

• Base-Files Project Base-Files: version 10.1ubuntu2.2 only
• Canonical Ubuntu Linux: version 18.04 only; version 18.10 only

Published 2018-08-21. Last modified 2026-06-17.