What is CVE-2021-47008?

CVE-2021-47008 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 5.11 onward and patched in 5.11.22, 5.12.5 and 5.13. CVE-2021-47008 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47008?

CVE-2021-47008 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-2021-47008?

Yes, CVE-2021-47008 has been patched. Fixed versions include 5.11.22, 5.12.5 and 5.13. If you are running Linux kernel 5.11 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47008 actively exploited?

CVE-2021-47008 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-2021-47008

Medium

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Make sure GHCB is mapped before updating Access to the GHCB is mainly in the VMGEXIT path and it is known that the GHCB will be mapped. But there are two paths where it is possible the GHCB might not be mapped. The sev_vcpu_deliver_sipi_vector() routine will update the GHCB to inform the caller of the AP Reset Hold NAE event that a SIPI has been delivered. However, if a SIPI is performed without a corresponding AP Reset Hold, then the GHCB might not be mapped (depending on the previous VMEXIT), which will result in a NULL pointer dereference. The svm_complete_emulated_msr() routine will update the GHCB to inform the caller of a RDMSR/WRMSR operation about any errors. While it is likely that the GHCB will be mapped in this situation, add a safe guard in this path to be certain a NULL pointer dereference is not encountered.

Package Linux Kernel

Published 2024-02-28

Last modified 2024-12-09

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-2021-47008 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 5.11 and later are affected. Fixed in 5.11.22, 5.12.5, 5.13 and their respective stable series.

Affected from

≥ 5.11

Fixed in

✓ 5.11.22 5.11.x ✓ 5.12.5 5.12.x ✓ 5.13

References

3 total

Kernel Git
https://git.kernel.org/stable/c/a3ba26ecfb569f4aa3f867e80c02aa65f20aadad

Patch
Kernel Git
https://git.kernel.org/stable/c/fb9e14f4f8217a0980f8da2c8ff70dee058cbe47

Patch
Kernel Git
https://git.kernel.org/stable/c/fd722a57fe0b80133dacae4e1c852ee4212f9b2e

Patch

Details

CVE ID CVE-2021-47008

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-02-28

Modified 2024-12-09

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47008?

CVE-2021-47008 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 5.11 onward and has been patched in 5.11.22, 5.12.5 and 5.13. CVE-2021-47008 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47008?

CVE-2021-47008 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-2021-47008?

Yes. CVE-2021-47008 has been patched. Fixed versions include 5.11.22, 5.12.5 and 5.13. If you are running Linux kernel 5.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47008 actively exploited?

No. CVE-2021-47008 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.