What is CVE-2021-47218?

CVE-2021-47218 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 5.8 onward and patched in 5.10.82, 5.15.5 and 5.16. CVE-2021-47218 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47218?

CVE-2021-47218 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-2021-47218?

Yes, CVE-2021-47218 has been patched. Fixed versions include 5.10.82, 5.15.5 and 5.16. If you are running Linux kernel 5.8 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47218 actively exploited?

CVE-2021-47218 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-2021-47218

Medium

In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails.

Package Linux Kernel

Published 2024-04-10

Last modified 2025-01-14

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-2021-47218 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 5.8 and later are affected. Fixed in 5.10.82, 5.15.5, 5.16 and their respective stable series.

Affected from

≥ 5.8

Fixed in

✓ 5.10.82 5.10.x ✓ 5.15.5 5.15.x ✓ 5.16

References

3 total

Kernel Git
https://git.kernel.org/stable/c/83c8ab8503adf56bf68dafc7a382f4946c87da79

Patch
Kernel Git
https://git.kernel.org/stable/c/b17dd53cac769dd13031b0ca34f90cc65e523fab

Patch
Kernel Git
https://git.kernel.org/stable/c/dc27f3c5d10c58069672215787a96b4fae01818b

Patch

Details

CVE ID CVE-2021-47218

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-04-10

Modified 2025-01-14

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47218?

CVE-2021-47218 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 5.8 onward and has been patched in 5.10.82, 5.15.5 and 5.16. CVE-2021-47218 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47218?

CVE-2021-47218 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-2021-47218?

Yes. CVE-2021-47218 has been patched. Fixed versions include 5.10.82, 5.15.5 and 5.16. If you are running Linux kernel 5.8 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47218 actively exploited?

No. CVE-2021-47218 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.