Security advisory

{
  "id": "83bc3b2bbb11b1fc594d9917a3d64c616c3c34b5c0551f37c5ba08cdcbca1ad6",
  "url": "https://osv.dev/vulnerability/CVE-2020-20277",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-20277",
    "summary": "There are multiple unauthenticated directory traversal vulnerabilities in different FTP commands in uftpd FTP server versions 2.7 to 2.10 due to improper implementation of a chroot jail in common.c's compose_abspath function that can be abused to read or write to arbitrary files on the filesystem, leak process memory, or potentially lead to remote code execution.",
    "evidence": "osv:CVE-2020-20277",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2020-20277",
      "aliases": [
        "CVE-2020-20277"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/troglobit/uftpd",
              "type": "GIT",
              "events": [
                {
                  "introduced": "b9c4a6fcb41427e1b3468141609173a41be6d947"
                },
                {
                  "last_affected": "e82248683ed7d53be1e01526f7b2a53dde545ef9"
                },
                {
                  "fixed": "455b47d3756aed162d2d0ef7f40b549f3b5b30fe"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:troglobit:uftpd:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.7"
                      },
                      {
                        "last_affected": "2.10"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "455b47d3756aed162d2d0ef7f40b549f3b5b30fe"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.10",
            "v2.9",
            "v2.8",
            "v2.7"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-20277.json",
            "vanir_signatures": [
              {
                "id": "CVE-2020-20277-6bb940c7",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "108229206972147259569248804372767412868",
                    "276360762841382069748424337075868013451",
                    "242312807191981524080516238265272007214",
                    "250357959569044888915036652998736230067"
                  ]
                },
                "source": "https://github.com/troglobit/uftpd/commit/455b47d3756aed162d2d0ef7f40b549f3b5b30fe",
                "target": {
                  "file": "src/common.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T13:52:40Z"
          }
        }
      ],
      "modified": "2026-10-20T13:52:40.072548819Z",
      "provider": "osv",
      "references": [
        "https://arinerron.com/blog/posts/6",
        "https://github.com/troglobit/uftpd/commit/455b47d3756aed162d2d0ef7f40b549f3b5b30fe"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-20277",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 388331,
  "published_at": "2020-12-18T19:15:14.11+00:00"
}