What is CVE-2021-29657?

CVE-2021-29657 is a High severity Linux kernel vulnerability with a CVSS score of 7.4 out of 10. CVE-2021-29657 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-29657?

CVE-2021-29657 has a CVSS score of 7.4 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2021-29657?

No patch is currently available for CVE-2021-29657. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-29657 actively exploited?

CVE-2021-29657 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2021-29657

High

arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.

Package Linux Kernel

Published 2021-07-22

Last modified 2024-11-21

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

7.4

out of 10

High

Attack Vector

Local

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-367

CVE-2021-29657 is classified as CWE-367

See CWE-367 on MITRE CWE for full details on this weakness type.

References

The following references provide additional information about CVE-2021-29657 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Packet Storm
http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html

Third Party Advisory VDB Entry
Security
https://security.netapp.com/advisory/ntap-20210902-0008/

Third Party Advisory
Kernel patch commit
https://bugs.chromium.org/p/project-zero/issues/detail?id=2177
Patch
Kernel patch commit
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12
Patch
Kernel patch commit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134
Patch

Details

CVE ID CVE-2021-29657

Severity High

CVSS score 7.4 / 10

CVSS version 3.1

Published 2021-07-22

Modified 2024-11-21

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2021-29657?

CVE-2021-29657 is a High severity Linux kernel vulnerability with a CVSS score of 7.4 out of 10 . CVE-2021-29657 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-29657?

CVE-2021-29657 has a CVSS score of 7.4 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2021-29657?

No patch is currently available for CVE-2021-29657. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-29657 actively exploited?

No — CVE-2021-29657 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.