CVE-2018-16841

Name: CVE-2018-16841
Creator: NVD / NIST
Published: 2018-11-28T14:29:00.347+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 4.59%

Last modified Jun 17, 2026

CVE-2018-16841 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Samba from version 4.3.0 and before versions 4.7.12, 4.8.7 and 4.9.3 are vulnerable to a denial of service. When configured to accept smart-card authentication, Samba's KDC will call talloc_free() twice on the same memory if the principal in a validly signed certificate does not match the principal in the AS-REQ. EPSS estimates a 4.59% chance of exploitation in the next 30 days.

Description

Samba from version 4.3.0 and before versions 4.7.12, 4.8.7 and 4.9.3 are vulnerable to a denial of service. When configured to accept smart-card authentication, Samba's KDC will call talloc_free() twice on the same memory if the principal in a validly signed certificate does not match the principal in the AS-REQ. This is only possible after authentication with a trusted certificate. talloc is robust against further corruption from a double-free with talloc_free() and directly calls abort(), terminating the KDC process.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

4.59%

90.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Samba	Samba	>= 4.3.0, < 4.7.12
Samba	Samba	>= 4.8.0, < 4.8.7
Samba	Samba	>= 4.9.0, < 4.9.3
Canonical	Ubuntu Linux	12.04
Canonical	Ubuntu Linux	14.04
Canonical	Ubuntu Linux	16.04
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	18.10
Debian	Debian Linux	9.0

References

http://www.securityfocus.com/bid/106023Third Party Advisory, VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16841Issue Tracking, Third Party Advisory
https://security.gentoo.org/glsa/202003-52Third Party Advisory
https://security.netapp.com/advisory/ntap-20181127-0001/Third Party Advisory
https://usn.ubuntu.com/3827-1/Third Party Advisory
https://usn.ubuntu.com/3827-2/Third Party Advisory
https://www.debian.org/security/2018/dsa-4345Third Party Advisory
https://www.samba.org/samba/security/CVE-2018-16841.htmlPatch, Vendor Advisory
http://www.securityfocus.com/bid/106023Third Party Advisory, VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16841Issue Tracking, Third Party Advisory
https://security.gentoo.org/glsa/202003-52Third Party Advisory
https://security.netapp.com/advisory/ntap-20181127-0001/Third Party Advisory
https://usn.ubuntu.com/3827-1/Third Party Advisory
https://usn.ubuntu.com/3827-2/Third Party Advisory
https://www.debian.org/security/2018/dsa-4345Third Party Advisory
https://www.samba.org/samba/security/CVE-2018-16841.htmlPatch, Vendor Advisory

Timeline

Published: Nov 28, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-16841?

How severe is CVE-2018-16841?

CVE-2018-16841 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 4.59% probability of exploitation in the next 30 days.

How do I fix CVE-2018-16841?

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-2018-16841?

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

Scan your code now

Source: NVD / NIST