TSGCTF2020 Reverse-ing

less than 1 minute read


Even though this is a reversing challenge, I thought I’d try to do the least amount of work and use Angr. Because this was labeled as an easy challenge, writing the angr solve script was also easy.


First, I ran file reversing to check whether or not the executable was stripped. This returned

reversing: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, not stripped

I also did a cursory check of the binary using Binary Ninja to make sure there was nothing too complicated going on which would make the symbolic execution take too long.

With these done, I began writing the python script.

Angr Solve

Running this gives us the solution!

Flag: TSGCTF{S0r3d3m0_b1n4ry_w4_M4wa77e1ru} Time elapsed: 137.10 seconds