T03 · Remote Payload Retrieval and Execution
Error
- Location
- scripts/reservation_toolkit.py:57
- Finding
- Untrusted Remote OpenVPN Configuration Is Executed Without Directive Validation## Vulnerability Details **File Location**: `scripts/reservation_toolkit.py`, lines 57–62 and 75–109 **Vulnerability Type**: Execution of remotely supplied active configuration **Risk Level**: High ### Vulnerable Code ```python def connect(self): if self.is_connected(): return subprocess.run(["pkill", "-f", "openvpn"], capture_output=True) time.sleep(2) if not Path(self.config_path).exists(): self._download_config() subprocess.run(["openvpn", "--config", self.config_path, "--daemon"], check=True) ``` ```python def _download_config(self): """Download best VPN Gate config with cipher fix.""" subprocess.run([ "curl", "-s", "https://www.vpngate.net/api/iphone/", "-o", "/tmp/vpn_list.csv" ], check=True) subprocess.run([ "python3", "-c", f""" import csv, base64 with open('/tmp/vpn_list.csv', newline='') as f: content = f.read() lines = content.split('\\n') data_lines = [l for l in lines if not l.startswith('*') and l.strip()] reader = csv.DictReader(data_lines) rows = list(reader) non_us = [r for r in rows if r.get('CountryShort','').strip() != 'US' and r.get('OpenVPN_ConfigData_Base64','').strip()] best = sorted(non_us, key=lambda s: int(s.get('Score',0)), reverse=True)[0] config = base64.b64decode(best['OpenVPN_ConfigData_Base64']).decode() if 'data-ciphers' not in config: lines2 = config.split('\\n') for i, line in enumerate(lines2): if line.startswith('cipher '): lines2.insert(i+1, 'data-ciphers AES-128-CBC:AES-256-GCM:AES-128-GCM') break config = '\\n'.join(lines2) with open('{self.config_path}', 'w') as f: f.write(config) print(f"Downloaded: {{best['CountryLong']}} {{best['IP']}}") """ ], capture_output=True, text=True, check=True) ``` ### Technical Analysis When a local VPN profile does not exist, the toolkit downloads a CSV feed from VPN Gate and selects a remotely supplied record based on its score and country. It Base6 ...[truncated 2275 chars]
- Remediation
- ## Remediation Suggestions 1. **Do not execute arbitrary profiles from the public listing.** Use a fixed, administratively reviewed profile or a curated allowlist of trusted profile fingerprints and endpoints. 2. **Parse profiles using a strict directive allowlist.** Permit only the minimum connection directives required for the supported setup. Reject script hooks, plugins, management interfaces, file-output directives, privilege changes, and all unknown directives. 3. **Avoid text-only keyword filtering.** Parse OpenVPN syntax correctly, including inline blocks, quoting, continuation behavior, and directive aliases. 4. **Require explicit approval before first activation.** Display the selected endpoint and validated profile summary, then require confirmation before invoking OpenVPN. 5. **Apply least privilege and isolation.** Run the VPN client in a dedicated container or network namespace with restricted filesystem access, dropped capabilities, and only the networking capabilities strictly required. 6. **Authenticate selected configuration material.** Pin a trusted source or verify profiles against administrator-maintained hashes or signatures before activation. 7. **Use safe temporary storage.** Replace the fixed `/tmp/vpn_list.csv` path with a securely created temporary file or process the response in memory, and ensure restrictive permissions for the final profile. 8. **Fail closed.** If profile parsing, validation, provenance checks, or isolation setup fails, do not invoke OpenVPN.