This Metasploit module attempts to exploit a netfilter bug on Linux Kernels befoe 4.6.3, and currently only works against Ubuntu 16.04 (not 16.04.1) with kernel 4.4.0-21-generic. Several conditions have to be met for successful exploitation: Ubuntu: 1. ip_tables.ko (ubuntu), iptable_raw (fedora) has to be loaded (root running iptables -L will do such) 2. libc6-dev-i386 (ubuntu), glibc-devel.i686