CVE intelligence and bounded remediation

CVE-2021-3631 — A flaw was found in libvirt while it generates SELinux MCS category pairs for VMs' dynamic labels

Medium CVSS 6.3

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.

Severity
Medium
CVSS
6.3 (3.1)
Published
2022-03-02
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-732

Affected products

  • redhat / libvirt
  • redhat / openshift_container_platform / 4.8
  • redhat / enterprise_linux / 8.0
  • netapp / ontap_select_deploy_administration_utility

Matched remediation archetype

Privilege escalation and unsafe privilege management

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map service accounts, operating-system identities, roles, capabilities, impersonation, set-user transitions, and administrative helper paths.
  • Determine whether untrusted users or lower-privilege processes can reach the affected transition or modify inputs it trusts.
  • Review file, socket, registry, device, job, container, and cloud-role permissions used before and after privilege changes.

Remediate safely

  • Apply the supported fix and redesign privileged operations as a minimal, authenticated, allowlisted interface.
  • Drop privileges before processing untrusted input, verify the drop succeeds, and remove unnecessary roles, capabilities, and write permissions.
  • Validate ownership and permissions at time of use and add explicit lower-to-higher privilege boundary tests.

Authoritative sources

Complete CVE record and remediation plan

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