def reset_due_date(request, course_id):
    """
    Rescinds a due date extension for a student on a particular unit.
    """
    course = get_course_by_id(SlashSeparatedCourseKey.from_deprecated_string(course_id))
    student = require_student_from_identifier(request.POST.get('student'))
    unit = find_unit(course, request.POST.get('url'))
    set_due_date_extension(course, unit, student, None)
    if not getattr(unit, "due", None):
        # It's possible the normal due date was deleted after an extension was granted:
        return JsonResponse(
            _("Successfully removed invalid due date extension (unit has no due date).")
        )

    original_due_date_str = unit.due.strftime('%Y-%m-%d %H:%M')
    return JsonResponse(_(
        'Successfully reset due date for student {0} for {1} '
        'to {2}').format(student.profile.name, _display_unit(unit),
                         original_due_date_str))
The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request.