CVE-2021-29657

HIGH

Linux Kernel 5.10-5.10.28 - Use-After-Free via Nested SVM VMCB12 Double Fetch

Title source: llm
STIX 2.1

Description

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.

References (5)

Core 5
Core References
Exploit, Mailing List, Patch, Third Party Advisory x_refsource_misc
https://bugs.chromium.org/p/project-zero/issues/detail?id=2177
Exploit, Patch, Vendor Advisory x_refsource_confirm
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12
Third Party Advisory x_refsource_confirm
https://security.netapp.com/advisory/ntap-20210902-0008/

Scores

CVSS v3 7.4
EPSS 0.0041
EPSS Percentile 32.7%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-367 CWE-416
Status published
Products (1)
linux/linux_kernel 5.10 - 5.10.28
Published Jul 22, 2021
Tracked Since Feb 18, 2026