GHSA-2f9h-23f7-8gcx AVideo affected by unauthenticated application takeover via exposed web installer on uninitialized deployments

• Packagist wwbn/avideo: <= 25.0 (no fix yet)

Summary The `install/checkConfiguration.php` endpoint performs full application initialization — database setup, admin account creation, and configuration file write — from unauthenticated POST input. The only guard is checking whether `videos/configuration.php` already exists. On uninitialized deployments, any remote attacker can complete the installation with attacker-controlled credentials and an attacker-controlled database, gaining full administrative access. Affected Component • `install/checkConfiguration.php` — entire file (lines 1-273) Description No authentication or access restriction on installer endpoint The `checkConfiguration.php` file performs the most privileged operations in the application — creating the database schema, the admin account, and the configuration file — with no authentication, no setup token, no CSRF protection, and no IP restriction. The sole guard is a file-existence check: ```php // install/checkConfiguration.php — lines 2-5 if (file_exists("../videos/configuration.php")) { error_log("Can not create configuration again: ". json_encode($_SERVER)); exit; } ``` If `videos/configuration.php` does not exist (fresh deployment, container restart without persistent storage, re-deployment), the entire installer runs with attacker-controlled POST parameters. Attacker-controlled database host eliminates credential guessing Unlike typical installer exposure vulnerabilities where the attacker must guess the target's database credentials, this endpoint allows the attacker to supply their own database host: ```php // install/checkConfiguration.php — line 25 $mysqli = @new mysqli($_POST['databaseHost'], $_POST['databaseUser'], $_POST['databasePass'], "", $_POST['databasePort']); ``` The attacker can: 1. Run their own MySQL server with the AVideo schema pre-loaded 2. Set `databaseHost` to their server's IP 3. The connection succeeds (attacker controls the DB) 4. The configuration file is written pointing the application at the attacker's database permanently Admin account creation with unsanitized input The admin user is created with direct POST parameter concatenation into SQL: ```php // install/checkConfiguration.php — line 120 $sql = "INSERT INTO users (id, user, email, password, created, modified, isAdmin) VALUES (1, 'admin', '" . $_POST['contactEmail'] . "', '" . md5($_POST['systemAdminPass']) . "', now(), now(), true)"; ``` This has two issues: (1) the attacker controls the admin password, and (2) `$_POST['contactEmail']` is directly concatenated into SQL without escaping (SQL injection). Configuration file written with attacker-controlled values The configuration file is written to disk with all attacker-supplied values embedded: ```php // install/checkConfiguration.php — lines 238-247 $videosDir = $_POST['systemRootPath'].'videos/'; if(!is_dir($videosDir)){ mkdir($videosDir, 0777, true); } $fp = fopen("{$videosDir}configuration.php", "wb"); fwrite($fp, $content); fclose($fp); ``` The `$content` variable (built at lines 188-236) embeds `$_POST['databaseHost']`, `$_POST['databaseUser']`, `$_POST['databasePass']`, `$_POST['webSiteRootURL']`, `$_POST['systemRootPath']`, and `$_POST['salt']` directly into the PHP configuration file. Inconsistent defense: CLI installer is protected, web endpoint is not The CLI installer (`install/install.php`) properly restricts access: ```php // install/install.php — lines 3-5 if (!isCommandLineInterface()) { die('Command Line only'); } ``` The web endpoint (`checkConfiguration.php`) lacks any equivalent protection, creating an inconsistent defense pattern. No web server protection on install directory There is no `.htaccess` file in the `install/` directory. The root `.htaccess` does not block access to `install/`. The endpoint is directly accessible at `/install/checkConfiguration.php`. Execution chain 1. Attacker discovers an AVideo instance where `videos/configuration.php` does not exist (fresh or re-deployed) 2. Attacker sends POST to `/install/checkConfiguration.php` with their own database host, admin password, and site configuration 3. The script connects to the attacker's database (or the target's with guessed/default credentials) 4. Tables are created, admin user is inserted with attacker's password 5. `configuration.php` is written to disk, permanently configuring the application 6. Attacker logs in as admin with full control over the application Proof of Concept Step 1: Set up an attacker-controlled MySQL server with the AVideo schema: ```bash On attacker's server mysql -e "CREATE DATABASE avideo;" mysql avideo error = "Setup token file not found. Create videos/.setup_token with a random secret."; header('Content-Type: application/json'); echo json_encode($obj); exit; } $expectedToken = trim(file_get_contents($setupTokenFile)); if (empty($_POST['setupToken']) || !hash_equals($expectedToken, $_POST['setupToken'])) { $obj = new stdClass(); $obj->error = "Invalid setup token."; header('Content-Type: application/json'); echo json_encode($obj); exit; } ``` Option 2: Restrict installer to localhost/CLI only Block web access to the installer entirely: ```php // At the top of install/checkConfiguration.php, after the file_exists check: if (!isCommandLineInterface()) { $allowedIPs = ['127.0.0.1', '::1']; if (!in_array($_SERVER['REMOTE_ADDR'], $allowedIPs)) { header('Content-Type: application/json'); echo json_encode(['error' => 'Installation is only allowed from localhost']); exit; } } ``` Additionally, add an `.htaccess` file in the `install/` directory: ```apache install/.htaccess Require local ``` Additional fixes needed 1. Parameterize SQL queries on line 120 to prevent SQL injection: ```php $stmt = $mysqli->prepare("INSERT INTO users (id, user, email, password, created, modified, isAdmin) VALUES (1, 'admin', ?, ?, now(), now(), true)"); $hashedPass = md5($_POST['systemAdminPass']); /…