Through_The_Router

Through The Router(200 pts)

Description

http://[SDN site]/Through_The_Router

How to run

Provided by SDN Site.

Comments

SDN rule conflict.

Find udp packet that occur rule conflict.

Flag

SCTF{Sp00f_7h3_p4ck3t_70_dr1ll_pr1v4t3_n37w0rk}

How to solve

The Rules.png shows IP and port filter rules with priorities. You will soon know that only packets from 10.1.7.8:5555 passes the firewall. Now you need to build a IP-spoofed packet. You can hand-craft one or even easier, use python library scapy:

from scapy.all import * 
(IP(src='10.1.7.8', dst='10.0.0.1') / UDP(sport=5555, dport=0x5678) / 'secret').build().encode('hex')