The access permissions for a UNIX domain socket are ignored in Solaris 2.x and SunOS 4.x, and other BSD-based operating systems before 4.4, which could allow local users to connect to the socket and possibly disrupt or control the operations of the program using that socket.
Expreserve, as used in vi and ex, allows local users to overwrite arbitrary files and gain root access.
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.