Security advisory

{
  "id": "f1954e5409ca7f47bc4a7a156275c3fe64b47a721246ffa4f7f71f66d85fdf37",
  "url": "https://osv.dev/vulnerability/CVE-2019-18978",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2019-18978",
    "summary": "An issue was discovered in the rack-cors (aka Rack CORS Middleware) gem before 1.0.4 for Ruby. It allows ../ directory traversal to access private resources because resource matching does not ensure that pathnames are in a canonical format.",
    "evidence": "osv:CVE-2019-18978",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2019-18978",
      "aliases": [
        "CVE-2019-18978",
        "GHSA-pf8f-w267-mq2h"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/cyu/rack-cors",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "e4d4fc362a4315808927011cbe5afcfe5486f17d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:rack-cors_project:rack-cors:*:*:*:*:*:ruby:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.0.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "e4d4fc362a4315808927011cbe5afcfe5486f17d"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.0.3",
            "v1.0.2",
            "v1.0.1",
            "v1.0.0",
            "v0.4.1",
            "v0.4.0",
            "v0.3.1",
            "v0.3.0",
            "v0.2.9",
            "v0.2.8",
            "v0.2.7",
            "v0.2.6",
            "v0.2.5",
            "v0.2.4",
            "v0.2.3",
            "v0.2.2",
            "v0.2.0",
            "v0.1.1",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-18978.json"
          }
        }
      ],
      "modified": "2026-10-20T10:50:50.762075954Z",
      "provider": "osv",
      "references": [
        "https://lists.debian.org/debian-lts-announce/2020/02/msg00004.html",
        "https://lists.debian.org/debian-lts-announce/2020/10/msg00000.html",
        "https://usn.ubuntu.com/4571-1/",
        "https://www.debian.org/security/2021/dsa-4918",
        "https://github.com/cyu/rack-cors/commit/e4d4fc362a4315808927011cbe5afcfe5486f17d",
        "https://github.com/cyu/rack-cors/compare/v1.0.3...v1.0.4"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*"
            ],
            "vendor_product": "canonical:ubuntu_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "16.04"
                  },
                  {
                    "last_affected": "16.04"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
              "cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*",
              "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "8.0"
                  },
                  {
                    "last_affected": "8.0"
                  },
                  {
                    "introduced": "9.0"
                  },
                  {
                    "last_affected": "9.0"
                  },
                  {
                    "introduced": "10.0"
                  },
                  {
                    "last_affected": "10.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2019-18978",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 382237,
  "published_at": "2019-11-14T21:15:12.17+00:00"
}