Oracle Java 7 Update 6, and possibly other versions, allows remote attackers to execute arbitrary code via a crafted applet, as exploited in the wild in August 2012 using Gondzz.class and Gondvv.class.
CVSS v2 Base Score: 6.8 (AV:N/AC:M/Au:N/C:P/I:P/A:P)
You're sitting in an office, and you send a print job to the main office printer. You see or hear a drone flying outside your window. Next thing you know, the printer buzzes to life and, after spitting out your print job, it continues to work and presents you with more filled pages than you expected.