#VU56018 Buffer overflow in Linux kernel - CVE-2021-22543
Published: August 20, 2021
Vulnerability identifier: #VU56018
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear
CVE-ID: CVE-2021-22543
CWE-ID: CWE-119
Exploitation vector: Local access
Exploit availability:
Public exploit is available
Vulnerable software:
Linux kernel
Linux kernel
Software vendor:
Linux Foundation
Linux Foundation
Description
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.
Remediation
Install updates from vendor's website.
External links
- https://github.com/google/security-research/security/advisories/GHSA-7wq5-phmq-m584
- http://www.openwall.com/lists/oss-security/2021/06/26/1
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ROQIXQB7ZAWI3KSGSHR6H5RDUWZI775S/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4G5YBUVEPHZYXMKNGBZ3S6INFCTEEL4E/