CVE-2021-22543

Public on 2021-08-13
Modified on 2021-10-04
Description
A flaw was found in the Linux kernel's KVM implementation, where improper handing of the VM_IO|VM_PFNMAP VMAs in KVM bypasses RO checks and leads to pages being freed while still accessible by the VMM and guest. This flaw allows users who can start and control a VM to read/write random pages of memory, resulting in local privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, and system availability.
Severity
Important
CVSS v3 Base Score
7.0
See breakdown

Affected Packages

Platform Package Release Date Advisory
Amazon Linux 2 kernel 2021-08-13 17:31 ALAS2-2021-1699
Amazon Linux 1 kernel 2021-09-30 19:25 ALAS-2021-1539

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD CVSSv2 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P
NVD CVSSv3 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H