CVE & CISA-KEV Catalog

CVE-2021-3671

MEDIUMEPSS 79th pctl

6.5

CVSS v3

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.

CWE-476NULL Pointer Dereference

How to fix

Remediation Available

heimdalDebian

Fixed in:7.7.0+dfsg-2+deb11u2CVE-2021-3671

Fixed in:7.7.0+dfsg-3CVE-2021-3671

Fixed in:7.7.0+dfsg-3CVE-2021-3671

Fixed in:7.7.0+dfsg-3CVE-2021-3671

heimdalUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

Fixed in:1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1USN-5675-1

Fixed in:7.5.0+dfsg-1ubuntu0.1USN-5675-1

Fixed in:7.7.0+dfsg-1ubuntu1.1USN-5675-1

heimdal-clientsUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

Fixed in:1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1USN-5675-1

Fixed in:7.5.0+dfsg-1ubuntu0.1USN-5675-1

Fixed in:7.7.0+dfsg-1ubuntu1.1USN-5675-1

heimdal-clients-xUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

heimdal-kcmUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

Fixed in:1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1USN-5675-1

Fixed in:7.5.0+dfsg-1ubuntu0.1USN-5675-1

Fixed in:7.7.0+dfsg-1ubuntu1.1USN-5675-1

heimdal-kdcUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

Fixed in:1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1USN-5675-1

Fixed in:7.5.0+dfsg-1ubuntu0.1USN-5675-1

Fixed in:7.7.0+dfsg-1ubuntu1.1USN-5675-1

heimdal-serversUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

Fixed in:1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1USN-5675-1

Fixed in:7.5.0+dfsg-1ubuntu0.1USN-5675-1

Fixed in:7.7.0+dfsg-1ubuntu1.1USN-5675-1

heimdal-servers-xUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

libgssapi3-heimdalUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

Fixed in:1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1USN-5675-1

Fixed in:7.5.0+dfsg-1ubuntu0.1USN-5675-1

Fixed in:7.7.0+dfsg-1ubuntu1.1USN-5675-1

libkdc2-heimdalUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

Fixed in:1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1USN-5675-1

Fixed in:7.5.0+dfsg-1ubuntu0.1USN-5675-1

Fixed in:7.7.0+dfsg-1ubuntu1.1USN-5675-1

libkrb5-26-heimdalUbuntu

Fixed in:1.6~git20131207+dfsg-1ubuntu1.2+esm1USN-5675-1

Fixed in:1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1USN-5675-1

Fixed in:7.5.0+dfsg-1ubuntu0.1USN-5675-1

Fixed in:7.7.0+dfsg-1ubuntu1.1USN-5675-1

sambaUbuntu

Fixed in:2:4.7.6+dfsg~ubuntu-0ubuntu2.26USN-5174-1

Fixed in:2:4.13.14+dfsg-0ubuntu0.20.04.1USN-5142-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

2.02%probability of exploitation in 30 days

79thpercentile

Elevated risk: more likely to be exploited than 79% of all known CVEs.

References

Patch1

github.com

Third-Party Advisory4

Other references2

Related Vulnerabilities

Other CWE-476 (NULL Pointer Dereference) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-21758	High	7.5	92%	-	Fix
CVE-2023-21547	High	7.5	88%	-	Fix
CVE-2014-3470	Medium	4.3	86%	-	Fix
CVE-2021-44224	High	8.2	82%	-	Fix
CVE-2016-0742	High	7.5	82%	-	Fix
CVE-2009-1386	Medium	5.0	80%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.