Rapid7 Vulnerability & Exploit Database

Ubuntu: USN-4948-1 (CVE-2021-29657): Linux kernel (OEM) vulnerabilities

Back to Search

Ubuntu: USN-4948-1 (CVE-2021-29657): Linux kernel (OEM) vulnerabilities

Severity
7
CVSS
(AV:L/AC:M/Au:N/C:C/I:C/A:C)
Published
05/11/2021
Created
05/14/2021
Added
05/12/2021
Modified
04/01/2022

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.

Solution(s)

  • ubuntu-upgrade-linux-image-5-10-0-1026-oem
  • ubuntu-upgrade-linux-image-oem-20-04b

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;