Recourse ManTrap 1.6 sets up a chroot environment to hide the fact that it is running, but the inode number for the resulting "/" file system is higher than normal, which allows attackers to determine that they are in a chroot environment.
https://exchange.xforce.ibmcloud.com/vulnerabilities/5472
http://marc.info/?l=bugtraq&m=97349791405580&w=2
http://archives.neohapsis.com/archives/bugtraq/2000-11/0100.html
http://archives.neohapsis.com/archives/bugtraq/2000-11/0041.html