YOURLS: Unauthenticated File Inclusion

{
  "id": "17bce68f2e1a179c41b5ab533f44f99189857cba7cc332248759dcd918aac0f2",
  "url": "https://osv.dev/vulnerability/GHSA-f8ff-652m-j5rx",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "YOURLS: Unauthenticated File Inclusion",
    "summary": "## Summary YOURLS versions ≤1.10.4 contain an unauthenticated path traversal vulnerability that allows attackers to include and execute arbitrary PHP files on the server without any credentials. ## Details The vulnerability exists because YOURLS uses **URL sanitization functions** (`yourls_sanitize_url()`, `yourls_esc_url()`) to filter request paths, but these functions are designed to clean URLs, not filesystem paths. They preserve `/` and `.` characters, allowing `../` sequences to pass through unfiltered. The unsanitized keyword is then directly concatenated into a filesystem path and passed to `file_exists()` and later `include()` operations, enabling path traversal attacks. **Data Flow:** ``` HTTP Request URI (with ../) ↓ yourls_get_request() (no sanitization) ↓ yourls_sanitize_url() (preserves / and .) ↓ yourls_esc_url() (permits / and . via regex) ↓ Keyword extraction (preserves ../) ↓ file_exists(YOURLS_PAGEDIR . \"/$keyword.php\") ← Sink ↓ include(YOURLS_PAGEDIR . \"/$keyword.php\") ← Code Execution ``` ## Proof of Concept (POC) In the concept validation, we assume that the attacker has uploaded a `test.php` file to the web root directory, but it cannot be accessed directly. (Of course, it could also be any path, such as `/tmp/test.php`) ### Setup Place a test file in web root: `./test.php`: ```php ``` ### Attack Request ```http GET /../../test HTTP/1.1 Host: target.com Connection: close ``` ### Response (Apache Environment) ## Impact 1. Remote execution of uploaded PHP ",
    "evidence": "osv:GHSA-f8ff-652m-j5rx",
    "products": [
      {
        "name": {
          "value": "yourls/yourls",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1.10.5",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "1.10.0",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.10.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.10.2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.10.3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.10.4",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.7.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.7.2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.7.3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.7.4",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.7.5",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.7.6",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.7.9",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.8",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.8.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.8.2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.9",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.9.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.9.2",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "GHSA-f8ff-652m-j5rx",
      "aliases": [
        "CVE-2026-62858",
        "GHSA-f8ff-652m-j5rx"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1.10.5"
                }
              ]
            }
          ],
          "package": {
            "name": "yourls/yourls",
            "purl": "pkg:composer/yourls/yourls",
            "ecosystem": "Packagist"
          },
          "versions": [
            "1.10.0",
            "1.10.1",
            "1.10.2",
            "1.10.3",
            "1.10.4",
            "1.7.1",
            "1.7.2",
            "1.7.3",
            "1.7.4",
            "1.7.5",
            "1.7.6",
            "1.7.9",
            "1.8",
            "1.8.1",
            "1.8.2",
            "1.9",
            "1.9.1",
            "1.9.2"
          ],
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-f8ff-652m-j5rx/GHSA-f8ff-652m-j5rx.json",
            "last_known_affected_version_range": "<= 1.10.4"
          }
        }
      ],
      "modified": "2026-10-15T20:30:06.075275041Z",
      "provider": "osv",
      "references": [
        "https://github.com/YOURLS/YOURLS/security/advisories/GHSA-f8ff-652m-j5rx",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-62858",
        "https://github.com/YOURLS/YOURLS/pull/4142",
        "https://github.com/YOURLS/YOURLS/commit/4e85972160a96e03a419a442d5bd8f21f2f02ddb",
        "https://github.com/YOURLS/YOURLS",
        "https://github.com/YOURLS/YOURLS/releases/tag/1.10.5"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-98"
        ],
        "severity": "MODERATE",
        "github_reviewed": true,
        "nvd_published_at": "2026-10-14T16:17:47Z",
        "github_reviewed_at": "2026-10-15T20:13:02Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-62858",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 336048,
  "published_at": "2026-10-15T20:13:02+00:00"
}