Collaborative Information Systems (CIS) contains aggregated information at one place. This information can be accessed by various categories of users for distinct or common purposes. As the users are diverse, security of system is an issue of utmost concern. Security issues can be both from outside world i.e. outsider threat as well as from authorized users of the system i.e. insider threat which proves even more difficult to detect. For outsider threat detection various access control models are implemented in almost all the information systems which grant privileges according to user's rights which are again based on their roles.