In trytond/model/modelstorage.py in Tryton 4.2 before 4.2.21, 4.4 before 4.4.19, 4.6 before 4.6.14, 4.8 before 4.8.10, and 5.0 before 5.0.6, an authenticated user can order records based on a field for which he has no access right. This may allow the user to guess values.