Multiple access validation errors in OutStart Participate Enterprise (PE) allow remote attackers to (1) browse arbitrary directory trees by modifying the rootFolder parameter to displaynavigator.jsp, (2) rename arbitrary directory objects by modifying the selectedObject parameter to renamepopup.jsp, (3) delete arbitrary directory objects by modifying the selectedObjectsCSV parameter to displaydeletenavigator.jsp, and conduct other unauthorized activities via the (4) showDeleteView, (5) showWebFolderView, (6) showLibraryView, (7) showMyLibraryView, (8) singleSelectObject, (9) processRadioSelection, (10) processCheckboxSelection, (11) singleSelectObject, (12) addToSelectedObjects, or (13) removeFromSelectedObjects commands.