Microsoft may be involved in negotiations to buy Israeli security firm Aorato, the company that reported a critical design flaw in the way Active Directory authenticates clients. Aorato is a startup that developed a solution (Directory Services Application Firewall) focused on the protection of the Active Directory service on Windows. In January, they received $10 / 7.4 million in funding from investors such as Accel, Trusteer co-founders, Innovation Endeavors and Glilot Capital Partner…