U.S Department of Homeland Security Industrial Control Systems Cyber Emergency Response Team (ICS-CERT)revealed last week that Westermo Ethernet industrial switches uses secure sockets layer (SSL)private keys which are hardcoded and shared across devices.
The Sweden-based company, Westermo is a supplier of high quality data communications equipment designed for harsh industrial applications. The firm’s solutions are used across the world in sectors such as transport, water, energy supplies, mining and petrochemical.
ICS-CERT discovered that using same SSL keys can be used by malicious actors to intercept and decrypt communications via a man-in-the-middle (MitM) attack and leverage the information to gain unauthorized access to a vulnerable device.
Even an attacker with low skill can exploit this flaw if they manage to launch a successful MitM attack on devices running versions 4.18 and earlier of WeOS, the operating system that powers Westermo’s hardware platforms.
The attack can affect Falcon, Wolverine, Lynx, Viper and RedFox.
The company is working on fixing the flaw by including the automate function of changing the key which will be included in WeOS 4.19 but for now the vendor has released an update that will allow users to change the problematic certificate in the web interface of the affected devices.
Meanwhile, users have been advised to update WeOS to the latest version and upload a custom certificate by following the instructions.
The affected company has also warned its customers to avoid self-signed certificates and either completely disable web access to the devices or limit access to secure networks.