Security advisory

{
  "id": "30d6f30d1cc05c16a225dc633b07f17bf77e73061cd89f4bcb58ab3f674e652c",
  "url": "https://osv.dev/vulnerability/CVE-2021-40540",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-40540",
    "summary": "ulfius_uri_logger in Ulfius HTTP Framework before 2.7.4 omits con_info initialization and a con_info->request NULL check for certain malformed HTTP requests.",
    "evidence": "osv:CVE-2021-40540",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2021-40540",
      "aliases": [
        "CVE-2021-40540"
      ],
      "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/babelouest/ulfius",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "845a5f471b0f2d2578b0997f531e503d31fda2ae"
                },
                {
                  "fixed": "c83f564c184a27145e07c274b305cabe943bbfaa"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:ulfius_project:ulfius:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.7.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c83f564c184a27145e07c274b305cabe943bbfaa"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.7.3",
            "v2.7.2",
            "v2.7.1",
            "v2.7.0",
            "v2.6.9",
            "v2.6.8",
            "v2.6.7",
            "v2.6.6",
            "v2.6.5",
            "v2.6.4",
            "v2.6.3",
            "v2.6.2",
            "v2.6.1",
            "v2.6.0",
            "v2.5.3",
            "v2.5.2",
            "v2.5.1",
            "v2.5.0",
            "v2.4.4",
            "v2.4.3",
            "v2.4.2",
            "v2.4.1",
            "v2.4.0",
            "v2.3.8",
            "v2.3.7",
            "v2.3.6",
            "v2.3.5",
            "v2.3.4",
            "v2.3.3",
            "v2.3.2",
            "v2.3.1",
            "v2.3.0",
            "v2.2.4",
            "v2.2.3",
            "v2.2.2",
            "v2.2.1",
            "v2.2",
            "2.1.2",
            "2.1.1",
            "2.1.0",
            "2.0.2",
            "2.0.1",
            "2.0.0",
            "1.0.4",
            "1.0.3",
            "1.0.2",
            "1.0.1",
            "1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-40540.json",
            "vanir_signatures": [
              {
                "id": "CVE-2021-40540-539cd306",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
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                },
                "source": "https://github.com/babelouest/ulfius/commit/c83f564c184a27145e07c274b305cabe943bbfaa",
                "target": {
                  "file": "src/ulfius.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2021-40540-6eff114a",
                "digest": {
                  "length": 1255,
                  "function_hash": "195028955909910763223043519064620928002"
                },
                "source": "https://github.com/babelouest/ulfius/commit/c83f564c184a27145e07c274b305cabe943bbfaa",
                "target": {
                  "file": "src/ulfius.c",
                  "function": "ulfius_uri_logger"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
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            ],
            "vanir_signatures_modified": "2026-10-20T14:29:22Z"
          }
        }
      ],
      "modified": "2026-10-20T14:29:22.813953472Z",
      "provider": "osv",
      "references": [
        "https://github.com/babelouest/ulfius/commit/c83f564c184a27145e07c274b305cabe943bbfaa",
        "https://github.com/babelouest/ulfius/compare/v2.7.3...v2.7.4"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-40540",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 389067,
  "published_at": "2021-09-07T02:15:07.13+00:00"
}