rpc.mountd on Linux, Ultrix, and possibly other operating systems, allows remote attackers to determine the existence of a file on the server by attempting to mount that file, which generates different error messages depending on whether the file exists or not.
The permissions for the /dev/audio device on Solaris 2.2 and earlier, and SunOS 4.1.x, allow any local user to read from the device, which could be used by an attacker to monitor conversations happening near a machine that has a microphone.