T09 · Insecure Skill Coding Practices
Warning
- Location
- scripts/searxng.py:72
- Finding
- Unvalidated SearXNG Endpoint Can Disclose Search Queries to an Unintended Service## Vulnerability Details **File Location**: `scripts/searxng.py`, lines 72-74, 101-117, and 168-171 **Vulnerability Type**: Unvalidated service endpoint and unsafe service discovery **Risk Level**: Medium ### Vulnerable Code ```python env_url = os.getenv("SEARXNG_URL") if env_url: return env_url.rstrip('/') ``` ```python common_ports = [8080, 8888, 9000, 8000] for port in common_ports: try: import socket sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(1) result = sock.connect_ex(("localhost", port)) sock.close() if result == 0: url = f"http://localhost:{port}" print(f"Found service at port {port}, assuming SearXNG: {url}", file=sys.stderr) return url except Exception: pass ``` ```python params = {'q': query, 'format': 'json'} url = f"{self.base_url}/search" try: async with session.get(url, params=params) as response: ``` ### Technical Analysis The `SEARXNG_URL` environment variable is accepted without validating its scheme, host, port, credentials, or path. Automatic discovery also assumes that any process listening on one of several common localhost ports is a SearXNG instance. No application-level request is performed to verify the identity of the selected service before user queries are transmitted. The selected endpoint receives the query through an HTTP GET request. Plain HTTP is permitted, and `aiohttp` follows redirects by default. Consequently, a malicious or incorrectly identified service can receive potentially sensitive search terms. If an attacker can influence the environment variable or operate a process on a probed port, the attacker can control where requests are sent. ### Attack Path 1. An attacker influences `SEARXNG_URL`, controls a service on one of the automatically probed localhost ports, or controls a selected endpoint that retu ...[truncated 839 chars]
- Remediation
- ## Remediation Suggestions - Parse endpoints with `urllib.parse.urlsplit` and allow only explicitly supported `http` and `https` schemes. - Reject embedded credentials, malformed hosts, unexpected paths, and unsupported URL schemes. - Require HTTPS for non-loopback endpoints. If local plain HTTP is necessary, restrict it to validated loopback addresses. - Apply an explicit allowlist of approved hosts or network ranges where deployment requirements permit it. - Verify discovered services through a SearXNG-specific API request and expected response structure rather than relying only on an open TCP port. - Disable redirects with `allow_redirects=False`, or validate every redirect target before following it. - Avoid silently selecting an arbitrary service on a common port. Require explicit confirmation or fail closed when service identity cannot be established. - Document the trust requirements for `SEARXNG_URL` and ensure untrusted callers cannot modify the process environment.