Apr 04, 2016
A security researcher has won $13,000 bounty from Microsoft for finding a critical flaw in its main authentication system that could allow hackers to gain access to a user's Outlook, Azure and Office accounts. The vulnerability has been uncovered by UK-based security consultant Jack Whitton and is similar to Microsoft's OAuth CSRF (Cross-Site Request Forgery) in Live.com discovered by Synack security researcher Wesley Wineberg. However, the main and only difference between the vulnerabilities is that: Flaw discovered by Wineberg affected Microsoft's OAuth protection mechanism while the one discovered by Whitton affected Microsoft's main authentication system. Microsoft handles authentication across its online services including Outlook, Azure and Office through requests made to login.live.com, login.windows.net, and login.microsoftonline.com. Now, for example, if a user browses to outlook.office.com, he/she redirects to a login.microsoftonline