Security advisory

{
  "id": "9de3d5686d85e9320bbb220d371acf98872ab04c9e43ed779be920a5f5ed9507",
  "url": "https://osv.dev/vulnerability/CVE-2020-21688",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-21688",
    "summary": "A heap-use-after-free in the av_freep function in libavutil/mem.c of FFmpeg 4.2 allows attackers to execute arbitrary code.",
    "evidence": "osv:CVE-2020-21688",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2020-21688",
      "aliases": [
        "CVE-2020-21688"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.ffmpeg.org/ffmpeg.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "517573a67088b5c7a25c18373434e3448892ee93"
                },
                {
                  "last_affected": "517573a67088b5c7a25c18373434e3448892ee93"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:ffmpeg:ffmpeg:4.2:-:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.2-NA"
                      },
                      {
                        "last_affected": "4.2-NA"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.2-NA",
            "n4.2-dev"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-21688.json"
          }
        },
        {
          "ranges": [
            {
              "repo": "https://github.com/ffmpeg/ffmpeg",
              "type": "GIT",
              "events": [
                {
                  "introduced": "517573a67088b5c7a25c18373434e3448892ee93"
                },
                {
                  "last_affected": "517573a67088b5c7a25c18373434e3448892ee93"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:ffmpeg:ffmpeg:4.2:-:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.2-NA"
                      },
                      {
                        "last_affected": "4.2-NA"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.2-NA",
            "n4.2-dev"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-21688.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:54.121901921Z",
      "provider": "osv",
      "references": [
        "https://www.debian.org/security/2021/dsa-4998",
        "https://trac.ffmpeg.org/ticket/8186"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "11.0"
                  },
                  {
                    "last_affected": "11.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2020-21688",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 438079,
  "published_at": "2021-08-10T21:15:07.723+00:00"
}