Under certain circumstances, invalid authentication credentials could be sent to the login endpoint of Johnson Controls Metasys NAE55, SNE, and SNC engines prior to versions 11.0.6 and 12.0.4 and Facility Explorer F4-SNC engines prior to versions 11.0.6 and 12.0.4 to cause denial-of-service.

Successful exploitation of this vulnerability could give an authenticated Facility Explorer SNC Series Supervisory Controller (F4-SNC) user an unintended level of access to the controller’s file system, allowing them to access or modify system files by sending specifically crafted web messages to the F4-SNC.