Impact

This vulnerability may allow attackers to spoof their IP address when your server is behind a reverse proxy.

Patches

Upgrade to v4.2.11 or later, and configure Config\App::$proxyIPs.

Workarounds

Do not use $request->getIPAddress().

References

• https://codeigniter4.github.io/userguide/incoming/request.html#CodeIgniter\HTTP\Request::getIPAddress

For more information

If you have any questions or comments about this advisory:

• Open an issue in codeigniter4/CodeIgniter4
• Email us at SECURITY.md