GHSA-m8r3-22v6-g877
REDAXO: Missing CSRF Protection on Package Update Action Allows Forced Addon Updates
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Packagist | redaxo/source | < 5.21.2 | 5.21.2 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Summary
The `rex_api_install_package_update` API function (`install` addon) does not override `requiresCsrfProtection()`, which defaults to `false` in the base class `rex_api_function`. Any authenticated admin can therefore be tricked via a CSRF attack into silently triggering a package update from the REDAXO package server.
### Details
**File:** `redaxo/src/core/lib/api_function.php:277-280`
```php
protected function requiresCsrfProtection()
{
return false; // DEFAULT — subclasses must opt in
}
```
**File:** `redaxo/src/addons/install/lib/api/api_package_update.php:8-39`
```php
class rex_api_install_package_update extends rex_api_function
{
public function execute()
{
if (!rex::getUser()?->isAdmin()) {
throw new rex_api_exception('You do not have the permission!');
}
$addonkey = rex_request('addonkey', 'string');
$fileId = rex_request('file', 'int');
$installer = new rex_install_package_update();
// ... downloads and installs $addonkey version $fileId from redaxo.org
}
// requiresCsrfProtection() NOT overridden — defaults to false
}
```
For comparison, `rex_api_install_package_add` and `rex_api_install_package_delete` both correctly return `true`. Only `rex_api_install_package_update` is missing this.
### PoC
```html
<!-- Attacker-controlled page -->
<img src="https://victim-redaxo.example.com/index.php?page=install/packages&rex-api-call=install_package_update&addonkey=some_addon&file=42" />
```
When an authenticated admin visits this page, the request is automatically made with their session cookie, causing `some_addon` to be updated to version `file_id=42`.
### Impact
An attacker who can lure an admin to a malicious page can force-install specific addon versions. If combined with a supply-chain compromise of a package on redaxo.org, or by targeting a downgrade to a known-vulnerable version, this becomes a remote code execution vector. Even without supply-chain compromise, it can be used to disrupt the site by forcing unwanted updates.
### Fix
Add `requiresCsrfProtection()` to `rex_api_install_package_update`:
```php
protected function requiresCsrfProtection()
{
return true;
}
```
References
External links from the advisory. They lead to third-party sites.