There is a site whose main page is in the format
http://example.com/index.php?page=1. It contains a rectangular box with text in it. What vulnerabilities can I use to find a hidden file on this site?
I have tried:
1) Putting another number or ASCII string instead of 1. It yields the same rectangular frame, but without text. I also tried putting a very large number and UTF-8 characters too, the result is the same. I get the same frame.
2) Checked the source code of pages. No results.