Tor clients can completely lose anonymity, confidentiality, and data integrity if the first Tor server in their path is malicious. Versions affected: stable versions up through 0.1.0.13 and experimental versions up through 0.1.1.4-alpha.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/39488/torHandshake.txt
Source: https://packetstormsecurity.com/files/39488/torHandshake.txt.html