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phpMyFAQ has an Authorization Bypass in All Admin Pages Due to Non-Terminating Permission Check

Moderate severity GitHub Reviewed Published Apr 28, 2026 in thorsten/phpMyFAQ • Updated Jun 9, 2026

Package

composer phpmyfaq/phpmyfaq (Composer)

Affected versions

<= 4.1.1

Patched versions

4.1.2
composer thorsten/phpmyfaq (Composer)
<= 4.1.1
4.1.2

Description

Summary

AbstractAdministrationController::userHasPermission() catches the ForbiddenException thrown when a user lacks a specific permission, sends a "forbidden" HTML page via $response->send(), but does not terminate execution. The calling controller method continues to execute, fetches protected data, renders the full template, and returns it as a Response. The final $response->send() in admin/index.php outputs the protected page content after the forbidden page, leaking all permission-protected admin data to any authenticated admin user regardless of their actual permissions.

Details

The parent class AbstractController::userHasPermission() (phpmyfaq/src/phpMyFAQ/Controller/AbstractController.php:317-327) correctly enforces authorization by throwing a ForbiddenException when the user lacks the required permission. This exception would normally propagate to Symfony's HttpKernel exception handler, which would return an error response and prevent the controller from continuing.

However, AbstractAdministrationController overrides this method at line 390-399:

#[\Override]
protected function userHasPermission(PermissionType $permissionType): void
{
    try {
        parent::userHasPermission($permissionType);
    } catch (ForbiddenException $exception) {
        $response = $this->getForbiddenPage($exception->getMessage());
        $response->send();  // Outputs HTML but does NOT terminate execution
    } catch (Exception $exception) {
        $this->configuration->getLogger()->error($exception->getMessage());
        // Only logs, no response, no termination
    }
}

The critical flaw: after $response->send() at line 396, there is no exit(), die(), return, or re-throw. PHP execution continues normally into the calling controller method.

For example, in AdminLogController::index() (phpmyfaq/src/phpMyFAQ/Controller/Administration/AdminLogController.php:45-83):

public function index(Request $request): Response
{
    $this->userHasPermission(PermissionType::STATISTICS_ADMINLOG);
    // ^^^ If user lacks permission: forbidden page is echoed, but execution continues

    // ... all of this still executes:
    $loggingData = $this->adminLog->getAll();  // Fetches ALL admin log entries
    // ...
    return $this->render('@admin/statistics/admin-log.twig', [
        // ... full admin log data including IPs, usernames, actions
        'loggingData' => $currentItems,
    ]);
}

The entry point admin/index.php then calls $response->send() on the returned Response, appending the full protected page to the already-sent forbidden page in the HTTP response body.

The second catch block (line 397-398) for generic Exception is even worse — it only logs the error without sending any response or terminating, so the protected page renders with no forbidden notice at all.

58 admin controllers extend AbstractAdministrationController and call userHasPermission(), meaning every permission-protected admin page is affected. This includes:

  • Admin logs (user IPs, actions, usernames)
  • User management (user data, permissions)
  • System information (server configuration, PHP info)
  • Configuration pages (all application settings)
  • Backup pages
  • All other admin functionality

PoC

  1. Create a test admin user with minimal permissions (e.g., only FAQ editing, no statistics access):

  2. Authenticate as the limited admin user and request a permission-protected page:

# Get admin session cookies by logging in
curl -c cookies.txt -d 'faqusername=limited_admin&faqpassword=password&pmf-csrf-token=TOKEN' \
  'https://TARGET/admin/?action=login'

# Access admin log page (requires STATISTICS_ADMINLOG permission)
curl -b cookies.txt -s 'https://TARGET/admin/statistics/admin-log' | tee response.html

# The response contains BOTH the forbidden page HTML AND the full admin log:
grep -c 'You are not allowed' response.html    # 1 — forbidden page was sent
grep -c 'loggingData\|ad_adminlog_ip' response.html  # matches — admin log data also present

# Access system information (requires CONFIGURATION_EDIT permission)  
curl -b cookies.txt -s 'https://TARGET/admin/system-information' | tee sysinfo.html
# Contains PHP version, extensions, database info, server configuration
  1. The HTTP response body contains the forbidden page HTML followed by the full protected page HTML, including all sensitive data.

Impact

Any authenticated admin user — even one with zero administrative permissions beyond basic login — can access every permission-protected admin page by simply requesting its URL. The permission check sends a forbidden page but does not stop execution, so the protected content is always appended to the response.

Exposed data includes:

  • Admin logs: All admin users' IP addresses, actions, and timestamps
  • User management: User accounts, email addresses, permissions
  • System information: PHP configuration, database details, server paths
  • Configuration: All application settings including security-sensitive values
  • Backups: Database export functionality

This effectively renders the entire admin permission system non-functional for the 58 page controllers using AbstractAdministrationController.

Recommended Fix

Add return after sending the forbidden response, and re-throw for the generic Exception case:

#[\Override]
protected function userHasPermission(PermissionType $permissionType): void
{
    try {
        parent::userHasPermission($permissionType);
    } catch (ForbiddenException $exception) {
        $response = $this->getForbiddenPage($exception->getMessage());
        $response->send();
        exit;  // Terminate execution to prevent controller from continuing
    } catch (Exception $exception) {
        $this->configuration->getLogger()->error($exception->getMessage());
        throw $exception;  // Re-throw to prevent controller from continuing
    }
}

A cleaner architectural fix would be to not swallow the exception at all, and instead let it propagate to the Symfony HttpKernel exception handler (which already handles ForbiddenException via WebExceptionListener):

#[\Override]
protected function userHasPermission(PermissionType $permissionType): void
{
    // Simply delegate to parent — let ForbiddenException propagate
    // to the WebExceptionListener which renders the appropriate error page
    parent::userHasPermission($permissionType);
}

Or remove the override entirely, since the WebExceptionListener registered in the Kernel already handles exception-to-response conversion.

References

@thorsten thorsten published to thorsten/phpMyFAQ Apr 28, 2026
Published to the GitHub Advisory Database May 6, 2026
Reviewed May 6, 2026
Last updated Jun 9, 2026

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
High
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:H/I:N/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(22nd percentile)

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.

CVE ID

CVE-2026-46362

GHSA ID

GHSA-hpgw-ww76-c68r

Source code

Credits

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