Rockwell Automation MicroLogix 1100 PLC < Series B FRN 12.0 MitM Replay Authentication Bypass

The Rockwell Automation MicroLogix 1100 PLC integrated web server has a firmware version that is prior to Series B FRN 12.0. It is, therefore, affected by an authentication bypass vulnerability due to a failure to properly restrict session replays. A man-in-the-middle attacker via HTTP traffic can use a session replay attack to bypass the web server’s authentication mechanism.

Note that Nessus has not attempted to exploit this issue but has instead relied only on the self-reported version number.