HIGH 7.4 Microsoft
CVE-2021-29657
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.
Microsoft Security Update 2021-Jul: 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 Products
- cm1 kernel 5.10.60.1-1 on CBL Mariner 1.0
- cbl2 kernel 5.10.78.1-1 on CBL Mariner 2.0
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-29657
- https://nvd.nist.gov/vuln/detail/CVE-2021-29657
This high severity vulnerability with a CVSS score of 7.4 was published on 2021-07-13 via Microsoft. Affected: cm1 kernel 5.10.60.1-1 on CBL Mariner 1.0, cbl2 kernel 5.10.78.1-1 on CBL Mariner 2.0.
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