Security advisory

{
  "id": "26213ede561a07d8264659b05fbb702318c1c3b90c6a9f33733e829ac5d5e041",
  "url": "https://osv.dev/vulnerability/CVE-2021-4120",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "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:CVE-2021-4120",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-4120",
      "aliases": [
        "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": [
            {
              "repo": "https://github.com/canonical/snapd",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "f6ff602cae4755eb38d1bbb20fa15752cb3b763a"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:canonical:snapd:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "2.54.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.54.2",
            "2.54.1",
            "2.54",
            "untagged-ec50ee5bfb45daefc236",
            "2.15.2",
            "2.15",
            "2.14.2.16.04",
            "2.14.1",
            "2.14",
            "2.13",
            "2.12",
            "2.11",
            "2.0.10",
            "2.0.9",
            "2.0.8",
            "2.0.7",
            "2.0.6",
            "2.0.5",
            "2.0.4",
            "2.0.3",
            "2.0",
            "1.9.4",
            "1.9.3",
            "1.9.2",
            "1.9.1",
            "1.9",
            "ppa",
            "1.7.3+20160310ubuntu1",
            "1.7.3+20160308ubuntu1",
            "1.7.3+20160303ubuntu4",
            "1.7.3+20160303ubuntu3",
            "1.7.3+20160303ubuntu2",
            "1.7.3+20160303ubuntu1",
            "1.7.3+20160225ubuntu1",
            "1.7.2+20160223ubuntu1",
            "1.7.2+20160204ubuntu1",
            "1.7.2+20160113ubuntu1",
            "1.7.2ubuntu1",
            "1.7ubuntu1",
            "1.6ubuntu1",
            "1.5ubuntu1",
            "1.4ubuntu1",
            "1.3ubuntu1",
            "1.2-0ubuntu1",
            "1.1.2-0ubuntu1",
            "1.1.1-0ubuntu1",
            "1.1-0ubuntu1",
            "1.0.1-0ubuntu1",
            "1.0-0ubuntu1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-4120.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:48.651181295Z",
      "provider": "osv",
      "references": [
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3QTBN7LLZISXIA4KU4UKDR27Q5PXDS2U/",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XCGHG6LJAVJJ72TMART6A7N4Z6MSTGI7/",
        "https://bugs.launchpad.net/snapd/+bug/1949368",
        "https://ubuntu.com/security/notices/USN-5292-1"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
              "cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*",
              "cpe:2.3:o:canonical:ubuntu_linux:21.10:*:*:*:*:*:*:*"
            ],
            "vendor_product": "canonical:ubuntu_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "18.04"
                  },
                  {
                    "last_affected": "18.04"
                  },
                  {
                    "introduced": "20.04"
                  },
                  {
                    "last_affected": "20.04"
                  },
                  {
                    "introduced": "21.10"
                  },
                  {
                    "last_affected": "21.10"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
              "cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "34"
                  },
                  {
                    "last_affected": "34"
                  },
                  {
                    "introduced": "35"
                  },
                  {
                    "last_affected": "35"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-4120",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 436814,
  "published_at": "2022-02-17T23:15:07.55+00:00"
}