A denial-of-service issue exists in 5380/5480/5580 controllers. This vulnerability could potentially allow a malicious user to write invalid file data to the controller, causing the device to enter a major non-recoverable fault (MNRF).
A specific malformed fragmented packet type (fragmented packets may be generated automatically by devices that send large amounts of data) can cause a major nonrecoverable fault (MNRF) Rockwell Automation's ControlLogix 5580, Guard Logix 5580, CompactLogix 5380, and 1756-EN4TR. If exploited, the affected product will become unavailable and require a manual restart to recover it. Additionally, an MNRF could result in a loss of view and/or control of connected devices.
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.