CVE-2018-6557

Name: CVE-2018-6557
Creator: NVD / NIST
Published: 2018-08-21T16:29:00.637+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7/10EPSS 0.36%

Last modified Jun 17, 2026

CVE-2018-6557 is a high-severity vulnerability rated 7/10 on the CVSS scale. 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.. EPSS estimates a 0.36% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7/10

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.36%

28.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-59

Affected Software

Vendor	Product	Versions
Base-Files Project	Base-Files	10.1ubuntu2.2
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	18.10

References

http://www.securityfocus.com/bid/105148Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1041530Broken Link, Third Party Advisory, VDB Entry
https://usn.ubuntu.com/3748-1/Vendor Advisory
http://www.securityfocus.com/bid/105148Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1041530Broken Link, Third Party Advisory, VDB Entry
https://usn.ubuntu.com/3748-1/Vendor Advisory

Timeline

Published: Aug 21, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-6557?

How severe is CVE-2018-6557?

CVE-2018-6557 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.

How do I fix CVE-2018-6557?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-6557?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST