GHSA-q4rm-m6xh-5pv7 Froxlor customer can create MySQL databases on disallowed servers via Mysqls.add API

• Packagist froxlor/froxlor: < 2.3.7 → fixed in 2.3.7

Summary The `Mysqls.add` API command (`lib/Froxlor/Api/Commands/Mysqls.php`) accepts a customer-controlled `mysql_server` parameter and only validates that the value is numeric and that the server index exists in `userdata.inc.php`. It never checks the value against the calling customer's `allowed_mysqlserver` allowlist. A customer can therefore create a database, plus a MySQL user with a password they choose, on any MySQL server the operator has configured — including servers that were explicitly excluded from that customer (e.g. a separate cluster, premium-tier host, or another tenant pool). The same `allowed_mysqlserver` check is correctly enforced in `MysqlServer::get()` / `MysqlServer::listing()` and in the customer-facing UI (`customer_mysql.php`), confirming the omission is a bug, not by-design. Details Vulnerable code path — `lib/Froxlor/Api/Commands/Mysqls.php:69-99` (`add()`): ```php public function add() { if (($this->getUserDetail('mysqls_used') getUserDetail('mysqls') || ...) { ... $customer = $this->getCustomerData('mysqls'); // line 80 $dbserver = $this->getParam('mysql_server', true, // line 81 — user-controlled $this->getDefaultMySqlServer($customer)); ... $dbserver = Validate::validate($dbserver, ..., '/^[0-9]+$/', ...); // line 92 — numeric only Database::needRoot(true, $dbserver, false); // line 93 — root ctx for ANY index Database::needSqlData(); $sql_root = Database::getSqlData(); Database::needRoot(false); if (!is_array($sql_root)) { // line 97 — only existence check throw new Exception("Database server with index #" . $dbserver . " is unknown", 404); } ... $username = $dbm->createDatabase($newdb_params['loginname'], $password, $dbserver, ...); // line 116/118 — DB+user created ... Database::pexecute($stmt, ["customerid"=>$customer['customerid'], ..., "dbserver"=>$dbserver], ...); } } ``` The `$customer['allowed_mysqlserver']` field IS read on line 80 but is only consumed by `getDefaultMySqlServer()` (lines 566-573) to compute a default when the request omits `mysql_server`. As soon as the client supplies the parameter, the default path is skipped and no further authorization gate runs. Cross-file evidence the check is intended elsewhere: • `lib/Froxlor/Api/Commands/MysqlServer.php:319-323` — `get()` rejects with HTTP 405 when `$dbserver` is not in `allowed_mysqlserver`: ```php if ($this->isAdmin() == false) { $allowed_mysqls = json_decode($this->getUserDetail('allowed_mysqlserver'), true); if ($allowed_mysqls === false || empty($allowed_mysqls) || !in_array($dbserver, $allowed_mysqls)) { throw new Exception("You cannot access this resource", 405); } ... } ``` • `lib/Froxlor/Api/Commands/MysqlServer.php:252-257` — same allowlist filter on `listing()`. • `customer_mysql.php:222` — UI rejects with `Response::dynamicError('No permission')` when `empty($allowed_mysqlservers)`. Chain of execution (attacker → impact): 1. Customer authenticates to `api.php` with apikey/secret. The only API gate is `cust_api_allowed`; `allowed_mysqlserver` is not consulted at auth time. 2. Customer sends JSON `{"command":"Mysqls.add","params":{"mysql_password":"","mysql_server":}}`. 3. `Mysqls.php:71` quota check passes (`mysqls_used _` (DbManager.php:177-218). 9. `Mysqls.php:127-141` inserts a row into `TABLE_PANEL_DATABASES` with the attacker's `customerid` and the disallowed `dbserver`, allowing later management via `Mysqls.get/update/delete` (which only filter by `customerid` for non-admins, e.g. `Mysqls.php:282`). PoC Preconditions on the target instance: • ≥2 MySQL servers configured in `lib/userdata.inc.php` (e.g. index 0 default, index 1 internal/premium). • Customer X with `allowed_mysqlserver=[0]`, `cust_api_allowed=1`, `mysqls > 0`, and an issued API key (`apikey:secret`). Request — customer creates a database on server `1`, which is *not* in their allowlist: ```bash curl -k -u 'CUST_APIKEY:CUST_SECRET' \ -H 'Content-Type: application/json' \ -X POST \ -d '{"command":"Mysqls.add","params":{"mysql_password":"ValidP@ssw0rd!","mysql_server":1}}' \ https://froxlor.example.com/api.php ``` Expected (mirroring `MysqlServer.get()` behaviour): `HTTP 405 — "You cannot access this resource"`. Actual: `HTTP 200` with the full database record, e.g.: ```json {"data":{"id":42,"customerid":,"databasename":"_sql1","dbserver":1,...}} ``` Verify the credentials work on the forbidden server: ```bash mysql -h server1.host -u _sql1 -p # password: ValidP@ssw0rd! mysql> SHOW DATABASES; # the new DB is present mysql> USE _sql1; # full access to the newly-created DB ``` The customer can subsequently manage the DB via `Mysqls.get`, `Mysqls.update`, and `Mysqls.delete` — those non-admin code paths filter only by `customerid` (`Mysqls.php:282-289`, `Mysqls.php:380-391`), which matches. Impact • Bypass of the per-customer MySQL-server allowlist (`allowed_mysqlserver`) enforced by the admin/reseller. The authorization model is fully defeated for the `add` operation. • The customer obtains valid MySQL credentials on a server the operator explicitly excluded for them — possibly an internal/separate cluster, billing tier, premium-only host, or a server provisioned for a different tenant pool. • The customer can persist a DB on the forbidden server (resource and policy bypass), then read/write data there, and continue to manage it through `Mysqls.update` / `Mysqls.delete`. • Impact is bounded: privileges granted by `DbManager::grantPrivilegesTo` apply only to the new `_sqlN` database, so no cross-tenant data exposure on the forbidden server. The damage is policy bypass, resource consumption on the forbidden server, and credential persistence there. Recommended Fix Mirror the allowlist check already present in `MysqlServer::get()`. After the numeric validation on `Mysqls.php:92`, before `Database::needRoot(...)`, add for non-admin callers: ```php // validate whether the dbserver exists $dbserver = Validate::validate($dbserver, html_entity_decode(lng('mysql.mysql_server')), '/^[0-9]+$/', '', 0, true); // enforce per-customer allowed_mysqlserver allowlist (parity with MysqlServer::get()) if (!$this->isAdmin()) { $allowed = json_decode($customer['allowed_mysqlserver'] ?? '[]', true); if (!is_array($allowed) || empty($allowed) || !in_array((int)$dbserver, array_map('intval', $allowed), true)) { throw new Exception('You cannot access this resource', 405); } } Database::needRoot(true, $dbserver, false); ``` Audit `Mysqls::update()`, `Mysqls::delete()`, and `Mysqls::get()` for the same gap: those endpoints accept `mysql_server` and ultimately call `Database::needRoot(true, $result['dbserver'], false)` on the row's stored value. Once the row exists with a forbidden `dbserver`, those paths execute against the forbidden server unchallenged. Consider rejecting any non-admin operation whose target row's `dbserver` is outside `allowed_mysqlserver`, even if the row already exists, to defend in depth.