CVE intelligence and bounded remediation

CVE-2020-27352 — Canonical Snapd security vulnerability

Critical CVSS 9.3

When generating the systemd service units for the docker snap (and other similar snaps), snapd does not specify Delegate=yes - as a result systemd will move processes from the containers created and managed by these snaps into the cgroup of the main daemon within the snap itself when reloading system units. This may grant additional privileges to a container within the snap that were not originally intended.

Severity
Critical
CVSS
9.3 (3.1)
Published
2024-06-21
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-269

Affected products

  • canonical / snapd
  • canonical / ubuntu_linux / 16.04
  • canonical / ubuntu_linux / 18.04
  • canonical / ubuntu_linux / 20.04
  • canonical / ubuntu_linux / 20.10

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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