Rating:

so... we were given a shell through ssh `ssh [email protected]` and ther was some restrictions that we couldn't use `cat` command to read the flag.

there is a looot of ways to bypass it. depending on how it's implemented. I have no idea why I choose this way among others, but I tried to raise an error by `exec < ./flag.txt` and it worked, showed the flag.txt content to say there is no such command/file `RaziCTF{th3r3_!s_4_c4t_c4ll3d_fl4g}`.

though of course before it reach the part that there is no such flag, it got that exclamination sign character and raised error about bash events.