On Unix-like operating systems (not Windows or macos), MPXJ's use of
File.createTempFile(..) results in temporary files being created with the permissions
-rw-r--r--. This means that any other user on the system can read the contents of this file. When MPXJ is reading a type of schedule file which requires the creation of a temporary file or directory, a knowledgeable local user could locate these transient files while they are in use and would then be able to read the schedule being processed by MPXJ.
The problem has been patched, MPXJ version 10.14.1 and later includes the necessary changes.
java.io.tmpdir to a directory to which only the user running the application has access will prevent other users from accessing these temporary files.
If you have any questions or comments about this advisory * Open an issue in https://github.com/joniles/mpxj