Plash permits sandboxed processes to open /dev/tty, which allows local users to escape sandbox restrictions and execute arbitrary commands by sending characters to a shell process on the same termimal via the TIOCSTI ioctl.
http://www.vupen.com/english/advisories/2007/0909
http://www.securityfocus.com/bid/22892
http://secunia.com/advisories/24498
http://plash.beasts.org/wiki/PlashIssues/TtyVulnerability
http://lists.gnu.org/archive/html/plash/2007-03/msg00000.html