CVE-2021-3738

Name: CVE-2021-3738
Creator: NVD / NIST
Published: 2022-03-02T23:15:09.07+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.84%

Last modified Jun 17, 2026

CVE-2021-3738 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. In DCE/RPC it is possible to share the handles (cookies for resource state) between multiple connections via a mechanism called 'association groups'. These handles can reference connections to our sam.ldb database. EPSS estimates a 1.84% chance of exploitation in the next 30 days.

Description

In DCE/RPC it is possible to share the handles (cookies for resource state) between multiple connections via a mechanism called 'association groups'. These handles can reference connections to our sam.ldb database. However while the database was correctly shared, the user credentials state was only pointed at, and when one connection within that association group ended, the database would be left pointing at an invalid 'struct session_info'. The most likely outcome here is a crash, but it is possible that the use-after-free could instead allow different user state to be pointed at and this might allow more privileged access.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

1.84%

76.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Samba	Samba	>= 4.0.0, < 4.13.14
Samba	Samba	>= 4.14.0, < 4.14.10
Samba	Samba	>= 4.15.0, < 4.15.2

References

https://bugzilla.redhat.com/show_bug.cgi?id=2021726Issue Tracking, Third Party Advisory
https://bugzilla.samba.org/show_bug.cgi?id=14468Issue Tracking, Patch, Vendor Advisory
https://security.gentoo.org/glsa/202309-06
https://www.samba.org/samba/security/CVE-2021-3738.htmlVendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2021726Issue Tracking, Third Party Advisory
https://bugzilla.samba.org/show_bug.cgi?id=14468Issue Tracking, Patch, Vendor Advisory
https://security.gentoo.org/glsa/202309-06
https://www.samba.org/samba/security/CVE-2021-3738.htmlVendor Advisory

Timeline

Published: Mar 2, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3738?

How severe is CVE-2021-3738?

CVE-2021-3738 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.84% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3738?

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-2021-3738?

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

Scan your code now

Source: NVD / NIST