Micrologix 1100 and 1400 controllers suffer from multiple vulnerabilities that allow unauthorized control of the PLC. Details of these vulnerabilities will be disclosed only to legitimate parties such as asset owners (utilities), after receiving the approval of the local CERT or any other local official entity.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/85192/micrologix-pwn.txt
Source: https://packetstormsecurity.com/files/85192/AB-Micrologix-Denial-Of-Service-Unauthorized-Access.html