CVE-2021-3631

Severity: medium (CVSS 6.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2022-03-02 · updated 2026-06-17
Weakness: CWE-732

Description

A flaw was found in libvirt while it generates SELinux MCS category pairs for VMs' dynamic labels. This flaw allows one exploited guest to access files labeled for another guest, resulting in the breaking out of sVirt confinement. The highest threat from this vulnerability is to confidentiality and integrity.

Affected products

NetApp ONTAP Select Deploy administration utility: all versions
Red Hat Enterprise Linux: 8.0
libvirt: before 7.5.0 — fixed in 7.5.0
Red Hat OpenShift Container Platform 4.18: 4.8

How to fix

Upgrade to a fixed version: libvirt 7.5.0. Check the vendor advisory for mitigations.

References

https://access.redhat.com/errata/RHSA-2021:3631
https://bugzilla.redhat.com/show_bug.cgi?id=1977726
https://gitlab.com/libvirt/libvirt/-/commit/15073504dbb624d3f6c911e85557019d3620fdb2
https://gitlab.com/libvirt/libvirt/-/issues/153
https://lists.debian.org/debian-lts-announce/2024/04/msg00000.html
https://security.gentoo.org/glsa/202210-06
https://security.netapp.com/advisory/ntap-20220331-0010/
https://access.redhat.com/errata/RHSA-2021:3631
https://bugzilla.redhat.com/show_bug.cgi?id=1977726
https://gitlab.com/libvirt/libvirt/-/commit/15073504dbb624d3f6c911e85557019d3620fdb2
https://gitlab.com/libvirt/libvirt/-/issues/153
https://lists.debian.org/debian-lts-announce/2024/04/msg00000.html

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