In an educational process oriented towards digital systems lot of things must be adapted to the new way of interaction between a student and a teacher. One of the most notable changes is the way results of particular assignments are treated. For example, if a teacher wants to assign a task to write a paper about medieval English literature for all participants in a course he would create an "Upload single file" activity.

By adding this and other kinds of activities that require the user to submit various types of files, poses potential security problems. Before going into more details let us expose all points of file submitting in Moodle available to the students...