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How the CVE Works:
The vulnerability resides in Symfony’s HttpFoundation Request class. This component is responsible for parsing incoming HTTP requests. Specifically, the code that handles the `PATH_INFO` server variable can, under certain web server configurations (like Apache with mod_php), generate a URL path that does not start with a forward slash (/). For example, a request to http://example.com/app.php/admin` might be incorrectly parsed as the path `admin` instead of/admin`. Many access control rules and security checks are written with the assumption that paths always begin with a ‘/’. This discrepancy allows an attacker to bypass these protections because the application’s security layer does not recognize `admin` as being equivalent to the protected `/admin` route, granting unauthorized access.
DailyCVE Form:
Platform: Symfony
Version: <5.4.x
Vulnerability: Auth Bypass
Severity: High
date: 2025-11-12
Prediction: Patch 2025-11-19
What Undercode Say:
Example request that might exploit the flaw on a vulnerable setup. curl http://vulnerable-host/app.phpadmin
// Example security rule that would be bypassed. $access_control = [ 'path' => '^/admin', // This regex does not match 'admin' 'roles' => 'ROLE_ADMIN' ];
How Exploit:
Craft requests to endpoints where the URL, after faulty parsing, lacks a leading slash. This causes the application’s path-based security checks to fail, allowing access to restricted areas without proper authorization.
Protection from this CVE:
Update Symfony to the patched version (5.4.x with the fix). The patch modifies the Request::preparePathInfo() method to always ensure the path starts with a forward slash.
Impact:
Limited authorization bypass, potentially granting unauthorized users access to protected application routes and functionalities.
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Sources:
Reported By: github.com
Extra Source Hub:
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