An entry in a sticky directory can be removed or renamed by a user only if the user has write permission for the directory and the user is the owner of the file, the owner of the directory, or the superuser. System Software Try to keep your operating system software as up to date as practical. Install all relevant patches to your operating system. Pay particular attention to security patches. The operating system vendor's home page should have a link to patches.
Most vendors have mailing lists which send out email when something needs to be upgraded.
NFS Be careful when exporting NFS directories. Wherever possible, file systems should be exported read-only. Do not self reference an NFS server in its own exports file. That is, the exports file should not export an NFS server to itself nor to any netgroups that include the NFS server. Export file systems only to hosts that require them.