roundup: privilege escalation in EditCSVAction

The EditCSVAction function in cgi/actions.py in Roundup 1.2 before 1.2.1, 1.4 through 1.4.6, and possibly other versions does not properly check permissions, which allows remote authenticated users with edit or create privileges for a class to modify arbitrary items within that class, as demonstrated by editing all queries, modifying settings, and adding roles to users.