The web server on the Siemens Scalance S Security Module firewall S602 V2, S612 V2, and S613 V2 with firmware before 2.3.0.3 does not limit the rate of authentication attempts, which makes it easier for remote attackers to obtain access via a brute-force attack on the administrative password.
http://www.us-cert.gov/control_systems/pdf/ICSA-12-102-05.pdf