Anubis has a bot protection bypass when a sophisticated attacker asks to pass a challenge of difficulty 0

{
  "id": "9ca977059e5f6ff3fb6bd01da0ae59a8cd688651f80d2193849dd2a251b3df01",
  "url": "https://osv.dev/vulnerability/CVE-2025-24369",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Anubis has a bot protection bypass when a sophisticated attacker asks to pass a challenge of difficulty 0",
    "summary": "Anubis is a tool that allows administrators to protect bots against AI scrapers through bot-checking heuristics and a proof-of-work challenge to discourage scraping from multiple IP addresses. Anubis allows attackers to bypass the bot protection by requesting a challenge, formulates any nonce (such as 42069), and then passes the challenge with difficulty zero. Commit e09d0226a628f04b1d80fd83bee777894a45cd02 fixes this behavior by not using a client-specified difficulty value.",
    "evidence": "osv:CVE-2025-24369",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2025-24369",
      "aliases": [
        "CVE-2025-24369",
        "GHSA-56w8-8ppj-2p4f",
        "GO-2025-3424"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/xe/x",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "7bd7b209f4f1b897de85ec8973458dc8be606a8b"
                },
                {
                  "fixed": "e09d0226a628f04b1d80fd83bee777894a45cd02"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "7bd7b209f4f1b897de85ec8973458dc8be606a8b"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "e09d0226a628f04b1d80fd83bee777894a45cd02"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.11.0",
            "v1.10.0",
            "v1.9.0",
            "v1.8.3",
            "v1.8.2",
            "v1.8.1",
            "v1.8.0",
            "v1.7.0",
            "v1.6.0",
            "v1.5.0",
            "v1.4.0",
            "v1.3.0",
            "v1.2.3",
            "v1.2.2",
            "v1.2.1",
            "v1.2.0",
            "v1.1.8",
            "v1.1.7",
            "v1.1.6",
            "v1.1.5",
            "v1.1.4",
            "v1.1.3",
            "v1.1.2",
            "v1.1.1-2-g18a0ab4",
            "v1.1.1-1-g95fdc95",
            "v1.1.1",
            "docker-base-layer",
            "v1.1.0",
            "v1.0.3",
            "v1.0.2",
            "v1.0.1",
            "v1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-24369.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.113199742Z",
      "provider": "osv",
      "references": [
        "https://xeiaso.net/notes/2025/GHSA-56w8-8ppj-2p4f",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/24xxx/CVE-2025-24369.json",
        "https://github.com/Xe/x/security/advisories/GHSA-56w8-8ppj-2p4f",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-24369",
        "https://github.com/Xe/x/commit/7bd7b209f4f1b897de85ec8973458dc8be606a8b",
        "https://github.com/Xe/x/commit/e09d0226a628f04b1d80fd83bee777894a45cd02"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-807"
        ],
        "cna_assigner": "GitHub_M",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "v1.11.0-37-gd98d70a"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/24xxx/CVE-2025-24369.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-24369",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517420,
  "published_at": "2025-01-27T22:57:26.728+00:00"
}