Privilege escalation in Red Hat Virtualization

Published: 2021-10-21
Risk Low
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-22543
Exploitation vector Local
Public exploit Public exploit code for vulnerability #1 is available.
Vulnerable software
redhat-virtualization-host (Red Hat package)
Operating systems & Components / Operating system package or component

redhat-release-virtualization-host (Red Hat package)
Operating systems & Components / Operating system package or component

Red Hat Virtualization Host
Web applications / Remote management & hosting panels

Red Hat Virtualization
Server applications / Virtualization software

Vendor Red Hat Inc.

Security Bulletin

This security bulletin contains one low risk vulnerability.

1) Buffer overflow

EUVDB-ID: #VU56018

Risk: Low


CVE-ID: CVE-2021-22543

CWE-ID: CWE-119 - Memory corruption

Exploit availability: Yes


The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error in Linux kernel when handling VM_IO|VM_PFNMAP vmas in KVM. A local user can  can bypass RO checks and cause the pages to get freed while still accessible by the VMM and guest. As a result, an attacker with the ability to start and control a VM to read/write random pages of memory, can trigger memory corruption and execute arbitrary code with elevated privileges.


Install updates from vendor's website.

Vulnerable software versions

redhat-virtualization-host (Red Hat package): 4.3.11-20200922.0.el7_9 - 4.3.18-20210903.0.el7_9

redhat-release-virtualization-host (Red Hat package): 4.3.4-1.el7ev - 4.3.18-1.el7ev

Red Hat Virtualization Host: 4

Red Hat Virtualization: 4

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?