Tridium Niagara AX Framework through 3.6 uses predictable values for (1) session IDs and (2) keys, which might allow remote attackers to bypass authentication via a brute-force attack.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2012-3002
http://www.us-cert.gov/control_systems/pdf/ICSA-12-228-01.pdf