Cisco Systems has warned of serious vulnerabilities in a device that connects a building’s ventilation, lighting, security, and energy supply systems so they can be controlled by IT workers remotely. The networking giant earlier this week (May 26) urged users of the Cisco Network Building Mediator products to patch the vulnerabilities, which among other things allow adversaries to obtain administrative passwords. No authentication is required to read the system configuration files, making it possible for outsiders to take control of a building’s most critical control systems. “Successful exploitation of any of these vulnerabilities could result in a malicious user taking complete control over an affected device,” a Cisco advisory stated. The notice also warned that the vulnerabilities are present in the legacy products from Richards-Zeta, the Cisco-acquired company that originally designed the system. The bugs were discovered during internal testing. Another flaw makes it possible for low-level employees to gain full control of the device by accessing default administrative accounts. Other bugs allowed malicious insiders to intercept traffic as it travels between an administrator and the building mediator and to escalate limited privileges.