WWBN AVideo is an open source video platform. In versions up to and including 26.0, the `getRealIpAddr()` function in `objects/functions.php` trusts user-controlled HTTP headers to determine the client's IP address. An attacker can spoof their IP address by sending forged headers, bypassing any IP-based access controls or audit logging. Commit 1a1df6a9377e5cc67d1d0ac8ef571f7abbffbc6c contains a patch.

Affected: Packagist: wwbn/avideo

## Summary

The `getRealIpAddr()` function in `objects/functions.php` trusts user-controlled HTTP headers to determine the client's IP address. An attacker can spoof their IP address by sending forged headers, bypassing any IP-based access controls or audit logging.

## Vulnerable Code

File: `objects/functions.php` ```php $headers = [ 'HTTP_X_REAL_IP', 'HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'REMOTE_ADDR' ];

foreach ($headers as $header) { if (!empty($_SERVER[$header])) { $ips = explode(',', $_SERVER[$header]); foreach ($ips as $ipCandidate) { $ipCandidate = trim($ipCandidate); if (filter_var($ipCandidate, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) { return $ipCandidate; } } } } ```

## Attack Scenario

1. Attacker sends request with forged header: ``` X-Client-IP: 127.0.0.1 ``` or ``` X-Real-IP: 192.168.1.1 ```

2. `getRealIpAddr()` returns the forged IP 3. Any IP-based rate limiting, access control, or audit log that relies on this function is bypassed

## Proof of Concept ```bash curl -H "X-Client-IP: 127.0.0.1" \ https://target.com/any_endpoint.php ```

The server now believes the request came from localhost.

## Impact - Bypass IP-based rate limiting - Bypass IP-based access controls - Forge audit log entries - Potential privilege escalation if localhost is trusted