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TI-2021-02996 Aliases CVE-2021-4120GHSA-hfvx-54vj-h9wq

snapd could be made to bypass intended access restrictions through snap content interfaces and layout paths

Priority LOW 36CWE-20Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

snapd 2.54.2 fails to perform sufficient validation of snap content interface and layout paths, resulting in the ability for snaps to inject arbitrary AppArmor policy rules via malformed content interface and layout declarations and hence escape strict snap confinement. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

Why it matters now

EPSS 0.00437 38th percentileScored 2026-11-08
Public exploit Yes 2 exploit referencesTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
Canonicalsnapdup to 2.54.2—No fix listedCNA
  • snapd VendorCanonical Affected up to 2.54.2 Fixed in — No fix listed CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:a:canonical:snapd:*:*:*:*:*:*:*:*up to 2.54.2VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*18.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*20.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:21.10:*:*:*:*:*:*:*21.10VulnerableCanonical
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*34VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*35VulnerableFedoraproject
  • cpe:2.3:a:canonical:snapd:*:*:*:*:*:*:*:* Versions up to 2.54.2 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* Versions 20.04 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:21.10:*:*:*:*:*:*:* Versions 21.10 Vulnerable ·Canonical
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* Versions 35 Vulnerable ·Fedoraproject

Remediation

No fixed version listed by the sources yet.

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Canonical snapd — FEDORA-2022-82bea71e5a

    3 records Highest priority Priority LOW 3 LOW

    Other records, highest priority first

    • TI-2021-20244 snapd could be made to escalate privileges and run programs as administratorPriority LOW 38
    • TI-2021-20245 snapd could be made to escalate privileges and run programs as administratorPriority LOW 36
    Show all 3 records → Advisory →
  • Advisory ·

    Canonical snapd — FEDORA-2022-5df8b52ba4

    3 records Highest priority Priority LOW 3 LOW

    Other records, highest priority first

    • TI-2021-20244 snapd could be made to escalate privileges and run programs as administratorPriority LOW 38
    • TI-2021-20245 snapd could be made to escalate privileges and run programs as administratorPriority LOW 36
    Show all 3 records → Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-4120
  2. 2026-10-03 Alias added: GHSA-hfvx-54vj-h9wq

References

Exploit 2

Patch 1

Advisory 2

  • TI-2023-01437 Injection in Canonical snapd CVSS 3.1CRITICAL 10.0
  • TI-2019-05192 Local privilege escalation via snapd socket CVSS 3.1CRITICAL 9.8
  • TI-2024-01603 snapd allows $HOME/bin symlink CVSS 3.1HIGH 8.2
  • TI-2024-04773 Improper input validation in Canonical snapd CVSS 3.1HIGH 8.1
  • TI-2020-16634 Improper privilege management in Canonical snapd CVSS 3.1CRITICAL 9.3
  • TI-2019-05191 Snapd seccomp filter TIOCSTI ioctl bypass CVSS 3.1HIGH 7.5
See all 15 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences