An attacker with the ability to modify a user program may change user program code on some ControlLogix, CompactLogix, and GuardLogix Control systems. Studio 5000 Logix Designer writes user-readable program code to a separate location than the executed compiled code, allowing an attacker to change one and not the other.
Rockwell Automation Studio 5000 Logix Designer (all versions) are vulnerable when an attacker who achieves administrator access on a workstation running Studio 5000 Logix Designer could inject controller code undetectable to a user.