CVE-2018-16851

Name: CVE-2018-16851
Creator: NVD / NIST
Published: 2018-11-28T14:29:00.423+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 3.25%

Last modified Jun 17, 2026

CVE-2018-16851 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Samba from version 4.0.0 and before versions 4.7.12, 4.8.7, 4.9.3 is vulnerable to a denial of service. During the processing of an LDAP search before Samba's AD DC returns the LDAP entries to the client, the entries are cached in a single memory object with a maximum size of 256MB. EPSS estimates a 3.25% chance of exploitation in the next 30 days.

Description

Samba from version 4.0.0 and before versions 4.7.12, 4.8.7, 4.9.3 is vulnerable to a denial of service. During the processing of an LDAP search before Samba's AD DC returns the LDAP entries to the client, the entries are cached in a single memory object with a maximum size of 256MB. When this size is reached, the Samba process providing the LDAP service will follow the NULL pointer, terminating the process. There is no further vulnerability associated with this issue, merely a denial of service.

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

3.25%

86.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Samba	Samba	>= 4.0.0, < 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	8.0
Debian	Debian Linux	9.0

References

http://www.securityfocus.com/bid/106027Third Party Advisory, VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16851Issue Tracking, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/12/msg00005.htmlMailing List, 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-2018-16851.htmlPatch, Vendor Advisory
http://www.securityfocus.com/bid/106027Third Party Advisory, VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16851Issue Tracking, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/12/msg00005.htmlMailing List, 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-2018-16851.htmlPatch, Vendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2018-16851?

How severe is CVE-2018-16851?

CVE-2018-16851 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 3.25% probability of exploitation in the next 30 days.

How do I fix CVE-2018-16851?

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-2018-16851?

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

Scan your code now

Source: NVD / NIST