CVE-2026-45262

## Summary > **Live PoC verified 2026-04-30** against a stock FacturaScripts master at `127.0.0.1:8081`. A scoped `ApiKey` with `fullaccess=0` and an `ApiAccess` row granting `allowget=1` on the `clientes` resource only (no other rights, no UI session, no admin) issued one `GET /api/3/clientes?filter[(0)UNION%20SELECT%20...]=` request and the response body contained the raw bcrypt hash of the admin user's password (`$2y$12$sLfA/XCqnjqLmYJwK.2V7eUHrHTHcQfkTYYfs1.lxX3OHrsmmkMGO`) and the admin's `logkey` cookie value. The leaked `logkey` was injected into a fresh cookie jar and `GET /AdminPlugins` returned 200 with the admin plugin management UI. End-to-end account takeover from a read-only token with no CSRF, no second factor, no rate-limit interaction beyond the default 5-incident IP throttle. `Core/Where.php::sqlColumn()` exempts any field name that contains both `(` and `)` from identifier escaping. The two API filter builders (`APIModel::getWhereValues` and `ApiAttachedFiles::getWhereValues`) feed the raw request key (`$_GET['filter'][$key]`) straight into `new DataBaseWhere($key, $value, '=', ...)`. When the model's `all()` reaches `Where::multiSqlLegacy` -> `Where::sql()` -> `Where::sqlColumn($key)`, the parenthesis branch returns the attacker-controlled string unmodified. The string is concatenated into `WHERE <attacker> = '<value>'`, which an attacker can pivot to `WHERE (0)UNION SELECT ... FROM users WHERE(nick='admin')-- = 'value'`, leaking arbitrary columns from any table. ## Details ### the API filter pipeline never validates filter keys `Core/Lib/API/APIModel.php:300-322` (`listAll`): ```php protected function listAll(): bool { $filter = $this->request->query->getArray('filter'); $limit = $this->request->query->getInt('limit', 50); $offset = $this->request->query->getInt('offset', 0); $operation = $this->request->query->getArray('operation'); $order = $this->request->query->getArray('sort'); // obtenemos los registros $