A website url was given. There was a login page which was vulnerable to SQLI. Just logged in with common SQLI payload: `' OR 1=1 --`
After Logging in, There was a ping service. Suspected Command Injection and tried few payloads. Got flag using this payload: `127.0.0.1 | cat /flag.txt`
After submitting the flag, I tried to see if solvers can modify the flag: `127.0.0.1 | echo 'lol' > /flag.txt`It did worked but I forgot what the flag was initially, so couldn't undo it. So changed it to this and contacted organizers:
![](https://i.ibb.co/7XXRpds/Screenshot-2021-04-09-Cybear-Networking-Systems.png)