Flag+

Description

Flag+ | 100 points | By Marvin

I've been trying to find a flag on this site, but it looks like you have to pay to get it...

Web servers: challs.bcactf.com:30313

Analysis

When trying to visit /flag.html we get message Looks like you clicked here from the free tier portal...

Solution

I used BurpSuite to inspect the requests. When /flag.html is requested there's interesting header.

Referer: http://challs.bcactf.com:30313/free.html

If we change it to /paid.html (which doesnt exist) /flag.html shows the flag.

Flag: bcactf{fl4g_r3ferr3d_gn3vhx75}