Fix CVE-2016-5696

#! /bin/bash

#Check root
if [ $(id -u) != "0" ];
then
    echo "Needs to be run by a user with root privilege."
    exit 1
fi

cvefix=`grep -o -E "net.ipv4.tcp_challenge_ack_limit = 999999999" /etc/sysctl.conf | wc -l`
if [ $cvefix -eq 0 ]; then
  echo 999999999 > /proc/sys/net/ipv4/tcp_challenge_ack_limit
  echo "net.ipv4.tcp_challenge_ack_limit = 999999999" >> /etc/sysctl.conf
  sysctl -p
else
    echo "  Skipping addition "
fi

echo "  Done. Press any key to continue."
read