CVE-2021-22543

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.

• CWE-119
• CWE-119

• http://www.openwall.com/lists/oss-security/2021/06/26/1Mailing List
• https://github.com/google/security-research/security/advisories/GHSA-7wq5-phmq-m584Exploit, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/10/msg00010.htmlMailing List, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/12/msg00012.htmlMailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4G5YBUVEPHZYXMKNGBZ3S6INFCTEEL4E/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ROQIXQB7ZAWI3KSGSHR6H5RDUWZI775S/
• https://security.netapp.com/advisory/ntap-20210708-0002/Third Party Advisory
• http://www.openwall.com/lists/oss-security/2021/06/26/1Mailing List
• https://github.com/google/security-research/security/advisories/GHSA-7wq5-phmq-m584Exploit, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/10/msg00010.htmlMailing List, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/12/msg00012.htmlMailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4G5YBUVEPHZYXMKNGBZ3S6INFCTEEL4E/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ROQIXQB7ZAWI3KSGSHR6H5RDUWZI775S/
• https://security.netapp.com/advisory/ntap-20210708-0002/Third Party Advisory

Published

May 26, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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