Security advisory

{
  "id": "0a1eb04dd951039c739ef763f04783dd6d3433f365626899557ccda76c6cde70",
  "url": "https://osv.dev/vulnerability/CVE-2019-5420",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2019-5420",
    "summary": "A remote code execution vulnerability in development mode Rails <5.2.2.1, <6.0.0.beta3 can allow an attacker to guess the automatically generated development mode secret token. This secret token can be used in combination with other Rails internals to escalate to a remote code execution exploit.",
    "evidence": "osv:CVE-2019-5420",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2019-5420",
      "aliases": [
        "CVE-2019-5420",
        "GHSA-m42h-mh85-4qgc"
      ],
      "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/rails/rails",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "e69ff43060c1194d2a3bd9b8d9e23f3ae26b84b5"
                },
                {
                  "introduced": "5a0230c67f852fb21173f99647e76336897446c1"
                },
                {
                  "last_affected": "5e6e505083c2b0caf85b2f86c6be3ff3d8750857"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "5.2.2.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:rubyonrails:rails:6.0.0:beta1:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "6.0.0-beta1"
                      },
                      {
                        "last_affected": "6.0.0-beta1"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:rubyonrails:rails:6.0.0:beta2:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "6.0.0-beta2"
                      },
                      {
                        "last_affected": "6.0.0-beta2"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "6.0.0-beta1",
            "6.0.0-beta2",
            "v6.0.0.beta2",
            "v5.2.2",
            "v6.0.0.beta1",
            "v5.2.2.rc1",
            "v5.2.1.rc1",
            "v5.2.0.rc1",
            "v5.1.0.beta1",
            "v5.0.0.beta4",
            "v5.0.0.beta2",
            "v5.0.0.beta1",
            "v4.2.0.beta1",
            "v4.0.0.rc1",
            "v4.0.0.beta1",
            "v3.2.0.rc1",
            "v3.1.0.rc1",
            "v3.1.0.beta1",
            "v3.0.0.beta3",
            "v3.0.0.beta.3",
            "v2.0.1",
            "v2.0.0",
            "v2.0.0_RC2",
            "v2.0.0_RC1",
            "v2.0.0_PR",
            "v1.1.1",
            "v1.1.0",
            "v1.1.0_RC1",
            "v0.14.3",
            "v0.14.1",
            "v0.13.1",
            "v0.13.0",
            "v0.12.0",
            "v0.11.1",
            "v0.11.0",
            "v0.10.1",
            "v0.10.0",
            "v0.9.5",
            "v0.9.4.1",
            "v0.9.4",
            "v0.9.3",
            "v0.9.2",
            "v0.9.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-5420.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:50.644524754Z",
      "provider": "osv",
      "references": [
        "https://groups.google.com/forum/#%21topic/rubyonrails-security/IsQKvDqZdKw",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA/",
        "https://weblog.rubyonrails.org/2019/3/13/Rails-4-2-5-1-5-1-6-2-have-been-released/",
        "https://www.exploit-db.com/exploits/46785/"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "8.0"
                  },
                  {
                    "last_affected": "8.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "30"
                  },
                  {
                    "last_affected": "30"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2019-5420",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 437292,
  "published_at": "2019-03-27T14:29:01.72+00:00"
}