CVE-2021-29657

CVSS V2 Medium 6.9 CVSS V3 High 7.4
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.
Overview
  • CVE ID
  • CVE-2021-29657
  • Assigner
  • cve@mitre.org
  • Vulnerability Status
  • Analyzed
  • Published Version
  • 2021-07-22T17:15:09
  • Last Modified Date
  • 2021-10-18T12:55:53
Weakness Enumerations
CWE URL
CWE-416 http://cwe.mitre.org/data/definitions/416.html
CPE Configuration (Product)
CPE Vulnerable Operator Version Start Version End
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 1 OR 5.11.12
CVSS Version 2
  • Version
  • 2.0
  • Vector String
  • AV:L/AC:M/Au:N/C:C/I:C/A:C
  • Access Vector
  • LOCAL
  • Access Compatibility
  • MEDIUM
  • Authentication
  • NONE
  • Confidentiality Impact
  • COMPLETE
  • Integrity Impact
  • COMPLETE
  • Availability Impact
  • COMPLETE
  • Base Score
  • 6.9
  • Severity
  • MEDIUM
  • Exploitability Score
  • 3.4
  • Impact Score
  • 10
CVSS Version 3
  • Version
  • 3.1
  • Vector String
  • CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
  • Attack Vector
  • LOCAL
  • Attack Compatibility
  • HIGH
  • Privileges Required
  • NONE
  • User Interaction
  • NONE
  • Scope
  • UNCHANGED
  • Confidentiality Impact
  • HIGH
  • Availability Impact
  • HIGH
  • Base Score
  • 7.4
  • Base Severity
  • HIGH
  • Exploitability Score
  • 1.4
  • Impact Score
  • 5.9
References
Reference URL Reference Tags
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134 Patch Third Party Advisory
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
http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html Third Party Advisory VDB Entry
https://security.netapp.com/advisory/ntap-20210902-0008/ Third Party Advisory
Sources
Source Name Source URL
NIST https://nvd.nist.gov/vuln/detail/CVE-2021-29657
MITRE https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29657
History
Created Old Value New Value Data Type Notes
2022-05-10 06:51:20 Added to TrackCVE
2022-12-05 06:48:24 2021-07-22T17:15Z 2021-07-22T17:15:09 CVE Published Date updated
2022-12-05 06:48:24 2021-10-18T12:55:53 CVE Modified Date updated
2022-12-05 06:48:24 Analyzed Vulnerability Status updated