What is CVE-2021-47223?

CVE-2021-47223 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a NULL Pointer Dereference flaw (CWE-476), affecting Linux kernel versions from 4.11 onward and patched in 4.14.238, 4.19.196, 5.4.128 and others. CVE-2021-47223 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47223?

CVE-2021-47223 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2021-47223?

Yes, CVE-2021-47223 has been patched. Fixed versions include 4.14.238, 4.19.196, 5.4.128 and others. If you are running Linux kernel 4.11 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47223 actively exploited?

CVE-2021-47223 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is NULL Pointer Dereference (CWE-476)?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/476.html

CVE-2021-47223

Medium

In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix vlan tunnel dst null pointer dereference This patch fixes a tunnel_dst null pointer dereference due to lockless access in the tunnel egress path. When deleting a vlan tunnel the tunnel_dst pointer is set to NULL without waiting a grace period (i.e. while it's still usable) and packets egressing are dereferencing it without checking. Use READ/WRITE_ONCE to annotate the lockless use of tunnel_id, use RCU for accessing tunnel_dst and make sure it is read only once and checked in the egress path. The dst is already properly RCU protected so we don't need to do anything fancy than to make sure tunnel_id and tunnel_dst are read only once and checked in the egress path.

Package Linux Kernel

Published 2024-05-21

Last modified 2025-02-03

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-476

CVE-2021-47223 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.11 and later are affected. Fixed in 4.14.238, 4.19.196, 5.4.128, 5.10.46, 5.12.13, 5.13 and their respective stable series.

Affected from

≥ 4.11

Fixed in

✓ 4.14.238 4.14.x ✓ 4.19.196 4.19.x ✓ 5.4.128 5.4.x ✓ 5.10.46 5.10.x ✓ 5.12.13 5.12.x ✓ 5.13

References

6 total

Kernel Git
https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530

Patch
Kernel Git
https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f

Patch
Kernel Git
https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c

Patch
Kernel Git
https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d

Patch
Kernel Git
https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79

Patch

Showing 5 of 6 references View all on NVD

Details

CVE ID CVE-2021-47223

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-05-21

Modified 2025-02-03

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47223?

CVE-2021-47223 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 4.11 onward and has been patched in 4.14.238, 4.19.196, 5.4.128 and others. CVE-2021-47223 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47223?

CVE-2021-47223 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2021-47223?

Yes. CVE-2021-47223 has been patched. Fixed versions include 4.14.238, 4.19.196, 5.4.128 and others. If you are running Linux kernel 4.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47223 actively exploited?

No. CVE-2021-47223 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.