CVE-2018-16851 Null dereference in samba

What is CVE-2018-16851?

CVE-2018-16851 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 28 Nov 2018. Any signed-in user can exploit it over the network, with no action from the victim.

Official 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.

Weakness: CWE-476

Which versions are affected by CVE-2018-16851?

It affects 3 products.

Products include Canonical Ubuntu Linux, Debian Debian Linux, Samba Samba.

How do I fix CVE-2018-16851?

Upgrade to a fixed version.

Is CVE-2018-16851 being exploited?

There is no known exploitation of CVE-2018-16851 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2018-16851, DEBIAN-CVE-2018-16851, ECHO-c8c0-89cd-58d0, GHSA-48v5-hp4g-w2rv, UBUNTU-CVE-2018-16851.