BigBlueButton hardening

Firewall

Script

• /usr/local/sbin/firewall

#!/bin/bash
iptables -F INPUT
case $1 in
start)
iptables -P INPUT DROP
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j ACCEPT
iptables -A INPUT -p tcp --dport 1935 -j ACCEPT
#iptables -A INPUT -p tcp --dport 5060 -j ACCEPT
#iptables -A INPUT -p udp --dport 5060 -j ACCEPT
#iptables -A INPUT -p tcp --dport 5080 -j ACCEPT
#iptables -A INPUT -p udp --dport 5080 -j ACCEPT
iptables -A INPUT -p tcp --dport 7443 -j ACCEPT
iptables -A INPUT -p udp --dport 16384:32768 -j ACCEPT
iptables -A INPUT -p icmp --icmp-type 8 -j ACCEPT
iptables -A INPUT -j LOG --log-prefix " --ipt-in-- "
;;
stop)
iptables -P INPUT ACCEPT
;;
esac

Unit

• /etc/systemd/system/firewall.service

[Unit]
Description=firewall
After=network.target syslog.target

[Service]
RemainAfterExit=yes
ExecStart=/usr/local/sbin/firewall start
ExecStop=/usr/local/sbin/firewall stop
User=root

[Install]
WantedBy=multi-user.target                      

Download

Datei:Firewall.tar.gz

Activate

• systemctl daemon-reload
• systemctl enable firewall.service
• systemctl start firewall.service

HSTS

• sed -ie '/ssl_dhparam/aadd_header Strict-Transport-Security "max-age=63072000; includeSubdomains;";' /etc/nginx/sites-enabled/bigbluebutton
• systemctl restart nginx

Check

• curl -s -D- https://video.xinux.de/ | grep -i Strict

Links

• https://andersgood.de/blog/bigbluebutton-auch-hinter-firewalls-nutzen