CVE-2021-29657

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

22/07/2021

Last modified:

19/05/2023

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.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.40 HIGH
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

7.40

Severity 3.x

HIGH

Vector 2.0

AV:L/AC:M/Au:N/C:C/I:C/A:C CVSS v2.0 Severity and Metrics:

Base Score: 6.90 MEDIUM
Vector: AV:L/AC:M/Au:N/C:C/I:C/A:C

Attack Vector (AV): Local
Attack Complexity (AC): Medium
Authentication (Au): None
Confidentiality (C): Complete
Integrity (I): Complete
Availability (A): Complete

Base Score 2.0

6.90

Severity 2.0

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:linux:linux_kernel::::::::	5.10 (including)	5.10.28 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.11 (including)	5.11.12 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-29657

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools