A brief write up discussing disclosure of internal IPs and hostnames from Apple bots leveraging Via and X-Forwarded-For headers.
You can download it from the following link: https://packetstormsecurity.com/files/download/159681/proxy-leakage.txt
Source: https://packetstormsecurity.com/files/159681/A-Short-Tale-Of-Proxy-Leakage.html