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PHP: Check REMOTE_ADDR and passed client IP

Requirement

Read access to the PHP source code and, if necessary, the proxy configuration.

Search for REMOTE_ADDR, X-Forwarded-For, CF-Connecting-IP and similar headers. The data flow afterwards is crucial: pure runtime checks, security decisions, log entries or persistent database columns are to be evaluated differently.

The specific read-only commands are collected under Check the website yourself.

Rate result

A single hit is a technical finding. Then check the purpose, actual storage, transfer and retention period of the affected level separately.

Classify in the overall check

This individual test only covers one level. Then systematically check the remaining levels using the checklist for unnecessary visitor data .

Related guides

• Caddy: Reconstruct original IP behind reverse proxy only if necessary
• Plausible proxy: Visitor IP is still passed on to Analytics
• Reverse Proxy: Check forwarding of the visitor IP at the origin
• Caddy: Reduce IP addresses in access logs

Sources and verification

This guide is based on multiple current sources. Vendor documentation is not treated as proof that every concrete installation automatically follows the same privacy characteristics.

• Self-test
• Inspection checklist

Important: IP processing is not IP storage

An IP address has to be processed to establish and deliver a network connection. Hosting providers, firewalls or DDoS protection may also process or retain it for a limited time for security purposes. No Logging distinguishes this security layer from unnecessary persistent visitor logging by the website, application and ordinary access logs.