Skip to content
Heist/ feed
Back to feed
HighFix available

snapd — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2021-4120

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

Products
snapd
Affected versions
Not specified
Fixed versions
2.54.3-1
CVEs
CVE-2021-4120
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 00:44 UTC · Revision 1

Source evidence

DEBIAN-CVE-2021-4120

core-osv · Original source

Published 17 Feb 2022, 23:15 UTC

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

osv:DEBIAN-CVE-2021-4120

snapd

Fixed versions: 2.54.3-1

snapd

Fixed versions: 2.54.3-1

snapd

Fixed versions: 2.54.3-1

Complete source record
{
  "id": "e44ae92144cb2ea5b21b8be8a9e71f903fd5e904e7312505526afb0e31b076ba",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-4120",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2021-4120",
    "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",
    "evidence": "osv:DEBIAN-CVE-2021-4120",
    "products": [
      {
        "name": {
          "value": "snapd",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.54.3-1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "snapd",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.54.3-1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "snapd",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.54.3-1",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "DEBIAN-CVE-2021-4120",
      "aliases": [
        "DEBIAN-CVE-2021-4120"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.54.3-1"
                }
              ]
            }
          ],
          "package": {
            "name": "snapd",
            "purl": "pkg:deb/debian/snapd?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-4120.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.54.3-1"
                }
              ]
            }
          ],
          "package": {
            "name": "snapd",
            "purl": "pkg:deb/debian/snapd?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-4120.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.54.3-1"
                }
              ]
            }
          ],
          "package": {
            "name": "snapd",
            "purl": "pkg:deb/debian/snapd?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-4120.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-23T18:03:38.675781656Z",
      "provider": "osv",
      "upstream": [
        "CVE-2021-4120"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2021-4120"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2021-4120",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 422117,
  "published_at": "2022-02-17T23:15:07.55+00:00"
}