Security advisory

{
  "id": "66e487d2767130dae9336469ef9ee794cb6386e0fb4c12a441a9100bc37392cd",
  "url": "https://osv.dev/vulnerability/CVE-2018-20820",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2018-20820",
    "summary": "read_ujpg in jpgcoder.cc in Dropbox Lepton 1.2.1 allows attackers to cause a denial-of-service (application runtime crash because of an integer overflow) via a crafted file.",
    "evidence": "osv:CVE-2018-20820",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2018-20820",
      "aliases": [
        "CVE-2018-20820"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/dropbox/lepton",
              "type": "GIT",
              "events": [
                {
                  "introduced": "c378cbfa2daaa99e8828be7395013f94cedb1bcc"
                },
                {
                  "last_affected": "c378cbfa2daaa99e8828be7395013f94cedb1bcc"
                },
                {
                  "fixed": "6a5ceefac1162783fffd9506a3de39c85c725761"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:dropbox:lepton:1.2.1:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.2.1"
                      },
                      {
                        "last_affected": "1.2.1"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "range": [
                      {
                        "fixed": "6a5ceefac1162783fffd9506a3de39c85c725761"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.2.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-20820.json",
            "vanir_signatures": [
              {
                "id": "CVE-2018-20820-7adfd9b9",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "291508219202119588538564923276176918018",
                    "96625002947938835274224164320718089154",
                    "213317746542680356999455718330753692033",
                    "173290755242118722020160640458997264056"
                  ]
                },
                "source": "https://github.com/dropbox/lepton/commit/6a5ceefac1162783fffd9506a3de39c85c725761",
                "target": {
                  "file": "src/lepton/jpgcoder.cc"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2018-20820-83a08037",
                "digest": {
                  "length": 6577,
                  "function_hash": "84036937326432341110227860591100513513"
                },
                "source": "https://github.com/dropbox/lepton/commit/6a5ceefac1162783fffd9506a3de39c85c725761",
                "target": {
                  "file": "src/lepton/jpgcoder.cc",
                  "function": "read_ujpg"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T13:44:52Z"
          }
        }
      ],
      "modified": "2026-10-20T13:44:52.973824565Z",
      "provider": "osv",
      "references": [
        "https://github.com/dropbox/lepton/commit/6a5ceefac1162783fffd9506a3de39c85c725761",
        "https://github.com/dropbox/lepton/issues/111"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2018-20820",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 388013,
  "published_at": "2019-04-23T14:29:00.367+00:00"
}