CVE-2021-29657
7.4 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
7.1 High
AI Score
Confidence
High
6.9 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:M/Au:N/C:C/I:C/A:C
0.003 Low
EPSS
Percentile
67.8%
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.
| CPE | Name | Operator | Version |
|---|---|---|---|
| linux:linux_kernel | linux linux kernel | lt | 5.10.28 |
| linux:linux_kernel | linux linux kernel | lt | 5.11.12 |
References
packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html
bugs.chromium.org/p/project-zero/issues/detail?id=2177
cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134
security.netapp.com/advisory/ntap-20210902-0008/
Social References
More
Related
7.4 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
7.1 High
AI Score
Confidence
High
6.9 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:M/Au:N/C:C/I:C/A:C
0.003 Low
EPSS
Percentile
67.8%