7.4

CVE-2021-29657

Exploit
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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 5.10 < 5.10.28
Linux ≫ Linux Kernel Version >= 5.11 < 5.11.12
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.41% 0.327
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 7.4 1.4 5.9
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd@nist.gov 6.9 3.4 10
AV:L/AC:M/Au:N/C:C/I:C/A:C
CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition

The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

CWE-416 Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

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
Patch
Third Party Advisory
Exploit
Mailing List
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12
Patch
Vendor Advisory
Exploit
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