Kerberos is vulnerable to replay in which of the following circumstances? 

Answer options:

A. When a private key is compromised within an allotted time window.
B. When a public key is compromised within an allotted time window.
C. When a ticket is compromised within an allotted time window.
D. When the KSD is compromised within an allotted time window.

C

Replay can be accomplished on Kerberos if the compromised tickets are used within an allotted time window. The security depends on careful implementation:enforcing limited lifetimes for authentication credentials minimizes the threat of of replayed credentials, the KDC must be physically secured, and it should be hardened, not permitting any non-kerberos activities. Reference: Official ISC2 Guide to the CISSP, 2007 Edition, page 184 also see: KRUTZ, Ronald L. & VINES, Russel
D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 42.