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Vulnerability · Published May 26, 2021 · Assigned by Google

CVE-2021-22543Improper memory handling in Linux KVM

High 8.7

In plain English

A high-severity memory corruption in Linux Kernel from Linux Kernel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.7%top 48.2% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

An issue was discovered in Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users with the ability to start and control a VM to read/write random pages of memory and can result in local privilege escalation.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8kernel-tools-libs-devel4.18.0-305.12.1.el8_4ALSA-2021:3057
Debian:12linux5.10.46-2DEBIAN-CVE-2021-22543
Debian:13linux5.10.46-2DEBIAN-CVE-2021-22543
Debian:14linux5.10.46-2DEBIAN-CVE-2021-22543
Rocky Linux:8kernel0:4.18.0-305.12.1.el8_4RLSA-2021:3057
Rocky Linux:8kernel-rt0:4.18.0-305.12.1.rt7.84.el8_4RLSA-2021:3088
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2021-22543
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-22543
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-22543
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-22543

Affected products (as reported)

VendorProductVersions
Linux Kernel Linux Kernel add6a0cd1c5ba51b201e1361b05a5df817083618 – before f8be156be163a052a067306417cd0ff679068c97

Weakness: CWE-119 · Vector: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L

References