The connection establishment algorithm found in Rockwell Automation CompactLogix 5370 and ControlLogix 5570 versions 33 and prior does not sufficiently manage its control flow during execution, creating an infinite loop. This may allow an attacker to send specially crafted CIP packet requests to a controller, which may cause denial-of-service conditions in communications with other products.

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.

An attacker could send a crafted HTTP/HTTPS request to render the web server unavailable and/or lead to remote code execution caused by a stack-based buffer overflow vulnerability. A cold restart is required for recovering CompactLogix 5370 L1, L2, and L3 Controllers, Compact GuardLogix 5370 controllers, and Armor Compact GuardLogix 5370 Controllers Versions 20 - 30 and earlier.

An attacker could send crafted SMTP packets to cause a denial-of-service condition where the controller enters a major non-recoverable faulted state (MNRF) in CompactLogix 5370 L1, L2, and L3 Controllers, Compact GuardLogix 5370 controllers, and Armor Compact GuardLogix 5370 Controllers Versions 20 - 30 and earlier.

In Rockwell Automation MicroLogix 1400 Controllers Series A, All Versions Series B, v15.002 and earlier, MicroLogix 1100 Controllers v14.00 and earlier, CompactLogix 5370 L1 controllers v30.014 and earlier, CompactLogix 5370 L2 controllers v30.014 and earlier, CompactLogix 5370 L3 controllers (includes CompactLogix GuardLogix controllers) v30.014 and earlier, an open redirect vulnerability could allow a remote unauthenticated attacker to input a malicious link to redirect users to a malicious site that could run or download arbitrary malware on the user’s machine.