CVE-2021-4093

A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES). A KVM guest using SEV-ES can trigger out-of-bounds reads and writes in the host kernel via a malicious VMGEXIT for a string I/O instruction (for example, outs or ins) using the exit reason SVM_EXIT_IOIO. This issue results in a crash of the entire system or a potential guest-to-host escape scenario.

CVSS v3.0 8.8 HIGH
CVSS v2.0 7.2 HIGH

8.8^/10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 2.0 / Impact : 6.0

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

7.2^/10

CVSS v2.0 : HIGH

V2 Legend

Vector : AV:L/AC:L/Au:N/C:C/I:C/A:C

Exploitability : 3.9 / Impact : 10.0

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

References

Link	Resource
https://bugs.chromium.org/p/project-zero/issues/detail?id=2222	Exploit Mailing List Patch Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2028584	Issue Tracking Patch Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*

Configuration 3 (hide)

cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*

Configuration 4 (hide)

OR	cpe:2.3:o:canonical:ubuntu_linux:20.04::::lts:::
	cpe:2.3:o:canonical:ubuntu_linux:21.10:::::::*

Information

Published : 2022-02-18 10:15

Updated : 2023-01-19 07:53

NVD link : CVE-2021-4093

Mitre link : CVE-2021-4093

JSON object : View

CWE

CWE-125

Out-of-bounds Read

CWE-787

Out-of-bounds Write

Products Affected

redhat

enterprise_linux

canonical

ubuntu_linux

fedoraproject

fedora

linux

linux_kernel

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8.8 /10