CVE-2021-3671

Name: CVE-2021-3671
Creator: NVD / NIST
Published: 2021-10-12T18:15:08.357+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 2.02%

Last modified Jun 17, 2026

CVE-2021-3671 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. A null pointer de-reference was found in the way samba kerberos server handled missing sname in TGS-REQ (Ticket Granting Server - Request). An authenticated user could use this flaw to crash the samba server.. EPSS estimates a 2.02% chance of exploitation in the next 30 days.

Description

A null pointer de-reference was found in the way samba kerberos server handled missing sname in TGS-REQ (Ticket Granting Server - Request). An authenticated user could use this flaw to crash the samba server.

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

2.02%

78.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Samba	Samba	< 4.13.12
Samba	Samba	>= 4.14.0, < 4.14.8
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0
Netapp	Management Services For Element Software	All versions
Netapp	Management Services For Netapp Hci	All versions
Netapp	Ontap Select Deploy Administration Utility	All versions

References

https://bugzilla.redhat.com/show_bug.cgi?id=2013080%2C
https://bugzilla.samba.org/show_bug.cgi?id=14770%2C
https://github.com/heimdal/heimdal/commit/04171147948d0a3636bc6374181926f0fb2ec83aPatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/11/msg00034.htmlMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20221215-0002/Third Party Advisory
https://security.netapp.com/advisory/ntap-20230216-0008/Third Party Advisory
https://www.debian.org/security/2022/dsa-5287Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2013080%2C
https://bugzilla.samba.org/show_bug.cgi?id=14770%2C
https://github.com/heimdal/heimdal/commit/04171147948d0a3636bc6374181926f0fb2ec83aPatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/11/msg00034.htmlMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20221215-0002/Third Party Advisory
https://security.netapp.com/advisory/ntap-20230216-0008/Third Party Advisory
https://www.debian.org/security/2022/dsa-5287Third Party Advisory

Timeline

Published: Oct 12, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3671?

How severe is CVE-2021-3671?

CVE-2021-3671 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 2.02% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3671?

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-2021-3671?

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

Scan your code now

Source: NVD / NIST