403 Forbidden Error While Sending GET Data

Question

My server is Linux server and reseller is mine. So i can reach WHM panel, too .

When GET data comes like :

a.php?url=http://www.domain.com
         


        

Answer 1

This is definitely one of the mod_security CoreRules. I've had the very same issue on my previous host. I don't remember the rule name however.

You should investigate the core rules version. 2.1.1 would be current, and might have relaxed that peculiar filter. If updating or reconfiguring doesn't help you would else have to base64_encode() your url parameter (simpler encodings are sniffed by mod_security).

SecFilterDebugLog /var/log/apache2/modsec_log
SecFilterDebugLevel 4

Enables the debug logging of mod_security, so you can find out which rule actually caused the issue - if you want to disable it (advisable). http://www.modsecurity.org/documentation/modsecurity-apache/1.9.3/modsecurity-manual.html#07-logging