In the past several years, there have been a large number of published works that have graphically described a wide variety of security problems particular to UNIX. Without fail, the same problems have been discussed over and over again, describing the problems with SUID (set user ID) programs, improper file permissions, and bad passwords (to name a few). There are two common characteristics to each of these problems: first, they are usually simple to correct, if found; second, they are fairly easy to detect. Since almost all systems have fairly equivalent problems, it seems appropriate to create a tool to detect potential security problems as an aid to system admin- istrators. This paper describes one such tool: COPS (Computer Oracle and Password System) is a freely-available, reconfigurable set of programs and shell scripts that enable system administrators to check for possible security holes in their systems. This paper briefly describes the system. Included are the underlying design goals, the functions provided by the tool, possible extensions, and some experiences gained from its use. We also include information on how to obtain a copy of the initial COPS release.