Admidio is an open-source user management solution. In versions 5.0.11 and prior, the modules/plugins.php endpoint handles plugin installation, uninstallation, and update operations via GET requests without CSRF token validation. Because these are top-level navigations, browsers include SameSite=Lax session cookies. An attacker crafts a malicious page that, when an authenticated administrator visits it, triggers arbitrary plugin operations. The uninstall operation executes DROP TABLE SQL scripts and destroys plugin data. This issue has been patched via commit 056b1bd.

Affected: Packagist: admidio/admidio

## Summary

The `modules/plugins.php` endpoint handles plugin installation, uninstallation, and update operations via GET requests without CSRF token validation. Because these are top-level navigations, browsers include `SameSite=Lax` session cookies. An attacker crafts a malicious page that, when an authenticated administrator visits it, triggers arbitrary plugin operations. The uninstall operation executes DROP TABLE SQL scripts and destroys plugin data.

## Details

`modules/plugins.php` reads the `mode` (install, uninstall, update) and `name` parameters directly from `$_GET`:

```php // modules/plugins.php $mode = admFuncVariableIsValid($_GET, 'mode', 'string'); $pluginName = admFuncVariableIsValid($_GET, 'name', 'string'); ```

The file contains zero calls to `SecurityUtils::validateCsrfToken()`. Other administrative operations in the same codebase (such as the `save` mode in preferences) validate CSRF tokens correctly.

Because the operations use GET requests, modern browsers send `SameSite=Lax` cookies on top-level GET navigations (link clicks, redirects, `window.location` assignments). A cross-origin page triggers these operations by navigating the browser to the vulnerable URL.

The `doUninstall()` function is the most destructive path. It executes SQL scripts from the plugin's `db_scripts/` directory, which contain `DROP TABLE` statements:

```php // modules/plugins.php - doUninstall() function doUninstall($pluginFolder) { // Reads and executes SQL from $plugin…