CVEvulnerability
CVE-2021-29657
7.4 HIGH
Official page ↗
- Status
- Modified
- Published
- 2021-07-22
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 7.4 HIGH — CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- CVSS 2.0 ([email protected])
- 6.9 MEDIUM — AV:L/AC:M/Au:N/C:C/I:C/A:C
- Weaknesses
- CWE-367, CWE-416
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.
Affected configurations
• linux linux kernel (>= 5.10 < 5.10.28)
• linux linux kernel (>= 5.11 < 5.11.12)
Related
References
- http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html Third Party Advisory, VDB Entry
- https://bugs.chromium.org/p/project-zero/issues/detail?id=2177 Exploit, Mailing List, Patch, Third Party Advisory
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12 Exploit, Patch, Vendor Advisory
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134 Patch, Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210902-0008/ Third Party Advisory
- http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html Third Party Advisory, VDB Entry
- https://bugs.chromium.org/p/project-zero/issues/detail?id=2177 Exploit, Mailing List, Patch, Third Party Advisory
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12 Exploit, Patch, Vendor Advisory
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134 Patch, Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210902-0008/ Third Party Advisory