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.
http://www.securityfocus.com/bid/456
http://www.iss.net/security_center/static/7172.php