Tag Archive: AS-REP

Aug 13

Active Directory Security Risk #101: Kerberos Unconstrained Delegation (or How Compromise of a Single Server Can Compromise the Domain)

At Black Hat USA 2015 this summer (2015), I spoke about the danger in having Kerberos Unconstrained Delegation configured in the environment. When Active Directory was first released with Windows 2000 Server, Microsoft had to provide a simple mechanism to support scenarios where a user authenticates to a Web Server via Kerberos and needs to …

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Sep 12

Kerberos, Active Directory’s Secret Decoder Ring

Kerberos Overview Kerberos is a protocol with roots in MIT named after the three-headed dog, Cerberus. Named because there are 3 parties: the client, the resource server, and a 3rd party (the Key Distribution Center, KDC). Kerberos can be a difficult authentication protocol to describe, so I will attempt to simplify it as best as …

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