Rockwell Automation CompactLogix, ControlLogix, Compact GuardLogix and GuardLogix

Three critical buffer overflow vulnerabilities in Rockwell Automation's CompactLogix, ControlLogix, Compact GuardLogix, and GuardLogix controllers allow remote attackers to trigger a Major Non-Recoverable Fault (MNRF), effectively taking industrial control systems offline without physical access. The root cause lies in improper input validation when processing project files or file write operations, a class of flaw that should be caught during secure development and patched promptly upon discovery. In operational technology (OT) environments, a controller entering an MNRF state can halt physical processes, creating safety risks beyond typical IT outages. The availability of patches makes continued exposure entirely preventable, yet many OT environments lag in patching due to uptime constraints and change management complexity. This highlights why ICS/SCADA assets require dedicated vulnerability management programs separate from standard IT patching cycles.