I joined a small ctf challenge and one of the challenges is that, given a webserver with a file on it, now you have to find the file on the server. The only thing that is given to you is, the url and the filename (flag.txt). I tried brute forcing common directories, google dorks, reverse shell... Nothing worked, so my last hope is to find the file due to its name.
So my question, is it possible to find a file on a webserver due to its file name?