The link leads to a portfolio site:
After poking around a bit we noticed that the images had strange looking links, for example:
If you flip this upside down it reads:
./img/work2.jpg. What would happen if we take the flags location
/home/bsidestlv/flag.txt and flip it in the same way?
To do this we collected a bunch of links from the site and using letters from them we managed to flip the location of the flag:
We navigated there and got the following response:
Error: ENOENT: no such file or directory, stat '/app/home/bsidestlv/flag.txt'.
It seems we landed in the wrong directory, let's try to go back one by adding
˙˙, new url:
This time we got the flag: