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Ordinary Authenticated User Can Access Admin-Only API Endpoints Due to Insufficient Authorization Check in phpMyFAQ

Moderate
thorsten published GHSA-jrc5-w569-h7h5 Apr 28, 2026

Package

No package listed

Affected versions

>= 4.1.1

Patched versions

4.1.2

Description

Summary

During a review of phpMyFAQ-main, I found an authorization issue in the admin-api routes.

Several backend endpoints only check whether the caller is logged in. They do not verify that the caller actually has backend or administrative privileges. As a result, a normal frontend user can access API endpoints that are clearly intended for administrative use.

In my local reproduction, a regular user account was able to request /admin/api/index.php/dashboard/versions and receive a successful response from the backend management API.

This issue does not appear to give direct write access in the affected paths I confirmed, so I would treat it as a backend information disclosure and privilege boundary failure rather than full admin compromise.

Details

The access control split is visible in the controller base class:

public function userIsAuthenticated(): void
{
    if (!$this->currentUser->isLoggedIn()) {
        throw new UnauthorizedHttpException('Unauthorized access.');
    }
}

protected function userHasPermission(PermissionType $permissionType): void
{
    // permission-based check
}

The problem is that several Administration\Api controllers use the weaker check even though the routes sit under the backend API namespace.

For example, phpmyfaq/src/phpMyFAQ/Controller/Administration/Api/DashboardController.php exposes:

#[Route(path: 'dashboard/versions', name: 'admin.api.dashboard.versions', methods: ['GET'])]
public function versions(): JsonResponse
{
    $this->userIsAuthenticated();
    ...
}

The same pattern appears in other backend-facing controllers, including:

  • LdapController
  • ElasticsearchController
  • OpenSearchController
  • UpdateController

That matters because these endpoints are not part of the normal frontend feature set. They expose backend operational data such as version checks, upgrade state, LDAP configuration, health checks, and search backend status.

Three examples that stand out from an impact perspective are:

  1. GET /admin/api/index.php/ldap/configuration

    This can expose LDAP server configuration, mapping settings, group settings, and general authentication-related options. Even with secrets masked, this is still useful internal infrastructure information.

  2. GET /admin/api/index.php/elasticsearch/statistics

    If Elasticsearch is enabled, this can expose index names and search backend statistics that should normally stay in the admin area.

  3. GET /admin/api/index.php/health-check

    This is part of the update and maintenance workflow and can reveal operational state that ordinary users should not be able to inspect.

In other words, the issue is not that guests can reach the backend. The issue is that any ordinary authenticated user can cross the frontend/backend privilege boundary.

PoC

I reproduced this against a local Docker deployment of the project.

First, an unauthenticated request to the backend API is rejected:

GET /admin/api/index.php/dashboard/versions HTTP/1.1
Host: 127.0.0.1
Accept: application/json

Response:

HTTP/1.0 401 Unauthorized
Content-Type: application/problem+json

{
  "type": "http://127.0.0.1/problems/unauthorized",
  "title": "Unauthorized",
  "status": 401,
  "detail": "Unauthorized access.",
  "instance": "/dashboard/versions"
}

Then I logged in with a normal frontend account:

  • username: user1
  • password: User12345!

After login, I sent the same request with the user session cookie:

GET /admin/api/index.php/dashboard/versions HTTP/1.1
Host: 127.0.0.1
Cookie: PHPSESSID=<regular-user-session>
Accept: application/json

Response:

HTTP/1.0 200 OK
Content-Type: application/json

{"success":"Latest version available: phpMyFAQ 4.1.1"}

That is enough to show that a non-admin account can call at least one backend management endpoint successfully.

Impact

The main impact is unauthorized access to backend-only operational information.

Depending on which optional features are enabled in a real deployment, this may let a normal user learn:

  • upgrade and version status
  • maintenance or health-check information
  • LDAP environment details
  • Elasticsearch or OpenSearch backend status and statistics
  • internal administrative diagnostics

I would rate this as Medium.

I am not calling it High because I did not confirm a direct administrative state change through the affected read-oriented endpoints. Still, this is a real privilege separation failure. A frontend account should not be able to query backend admin APIs simply because it has a valid session.

Remediation

I would suggest fixing this in two layers.

  1. Replace userIsAuthenticated() with explicit permission checks on backend endpoints that are intended for administrators only.
  2. Review all Administration\Api controllers for similar cases and make the access model consistent.
  3. Keep backend operational endpoints separated from ordinary user sessions unless there is a strong business reason to expose them.
  4. Add regression tests that log in as a low-privileged user and verify that backend routes return 403 or 401 where appropriate.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVE ID

No known CVE

Weaknesses

Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. Learn more on MITRE.

Credits