PRIOn knowledge basePRION:CVE-2021-29657Race condition
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
67.5%
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_kernel | ge | 5.10 | |
| linux_kernel | lt | 5.10.28 | |
| linux_kernel | ge | 5.11 | |
| 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/
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
67.5%