TLDR; This is a two part problem. In part 1, we implement a simple `pwntools` script to eval math statements and discover a script and exfiltrates some data to an external server. In part 2, we have the network capture of the data exfiltration, which has to be reversed to get back the original information, which is the flag. 
https://meashiri.github.io/ctf-writeups/posts/202308-sekaictf/#eval-me