Talkd, when given corrupt DNS information, can be used to execute arbitrary commands with root privileges.

AUSCERT:AA-97.01 | CERT:CA-97.04.talkd | FREEBSD:FreeBSD-SA-96:21 | SUN:00147 | URL:http://sunsolve.sun.com/pub-cgi/retrieve.pl?doctype=coll&doc=secbull/147 | XF:netkit-talkd | XF:talkd-bo