Security advisory

{
  "id": "fc3ca1b5f9fa826d421fd3a43d59253b838e34eba066fa165b33045f0072abb1",
  "url": "https://osv.dev/vulnerability/CVE-2021-36766",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-36766",
    "summary": "Concrete5 through 8.5.5 deserializes Untrusted Data. The vulnerable code is located within the controllers/single_page/dashboard/system/environment/logging.php Logging::update_logging() method. User input passed through the logFile request parameter is not properly sanitized before being used in a call to the file_exists() PHP function. This can be exploited by malicious users to inject arbitrary PHP objects into the application scope (PHP Object Injection via phar:// stream wrapper), allowing them to carry out a variety of attacks, such as executing arbitrary PHP code.",
    "evidence": "osv:CVE-2021-36766",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-36766",
      "aliases": [
        "CVE-2021-36766"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/concretecms/concretecms",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "f9c8e08d3651a250f42e0c0a8cc18bc64b42733f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "8.5.6"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "8.4.1",
            "8.3.1",
            "8.2.1",
            "8.2.0",
            "8.2.0RC2",
            "8.1.0",
            "5.7.5.7",
            "5.7.5.6",
            "5.7.5.5",
            "5.7.5.2",
            "5.7.4.1",
            "5.7.3.1",
            "5.7.3",
            "5.7.2.1",
            "5.7.2",
            "5.7.0.4",
            "5.7.1",
            "5.7.0.3",
            "5.7.0.1",
            "5.7.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-36766.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:20.803383795Z",
      "provider": "osv",
      "references": [
        "https://hackerone.com/reports/1063039"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-36766",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 430342,
  "published_at": "2021-07-30T14:15:18.283+00:00"
}