Jailed Shell Escape
- http://netsec.ws/?p=337
- https://pen-testing.sans.org/blog/2012/06/06/escaping-restricted-linux-shells
- https://speakerdeck.com/knaps/escape-from-shellcatraz-breaking-out-of-restricted-unix-shells
- http://airnesstheman.blogspot.ca/2011/05/breaking-out-of-jail-restricted-shell.html
- http://securebean.blogspot.ca/2014/05/escaping-restricted-shell_3.html