MIMAnet Source Viewer is a freely available CGI script which allows users to view the source code of files located elsewhere on the server.
Source Viewer accepts an argument, 'loc', which it uses as the filename when opening the requested file. Unfortunately it does not filter '..' and '/' characters, which can be misinterpreted by the script and cause files outside of the intended directory to be opened. As a result, it may be possible for attackers to view the contents of arbitrary webserver-readable files on the filesystem.
The following URL demonstrates the problem:
loc=../[any file outside restricted directory]