Phoenix Contact GmbH & Co. KG created a mitigation plan that includes an update and recommended security practices to mitigate authentication vulnerabilities in its ILC (inline controller) PLCs these vulnerabilities, according to a report with ICS-CERT.
These vulnerabilities, discovered by Matthias Niedermaier and Michael Kapfer of HSASec Hochschule Augsburg, are remotely exploitable.
All ILC 1xx PLCs versions suffer from the vulnerabilities.
The identified vulnerabilities could allow an unauthenticated user to access human-machine interface (HMI) pages and to modify programmable logic controller (PLC) variables.
Phoenix Contact GmbH & Co. KG is a German-based automation company.
The affected products, ILC 1xx PLCs, are inline controllers with an Ethernet interface for coupling to other controllers and systems. ILC PLCs see action across several sectors including commercial facilities, critical manufacturing, energy, and water and wastewater systems. Phoenix Contact said these products see use primarily in Europe, North America, and Asia.
Webvisit offers a password macro to protect HMI pages on the PLC against casual or coincidental opening of HMI pages by the user. The password macro can end up configured in a way the password ends up stored and transferred in clear text.
CVE-2016-8366 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 7.3.
In addition, the web server can end up accessed without authenticating even if the authentication mechanism is enabled.
CVE-2016-8371 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 7.3.
Also, the web server allows access to read and write PLC variables without authentication.
CVE-2016-8380 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 7.3.
No known public exploits specifically target these vulnerabilities. However, an attacker with a low skill would be able to exploit these vulnerabilities.
Phoenix Contact released an update for Webvisit to mitigate the plaintext password storage issue. Users may obtain this update by emailing Phoenix Contact customer support.
Connecting devices to a network via Ethernet always entails the risk of unauthorized access to the network. Phoenix Contact recommends users implement an adequate defense–in-depth networking architecture (including the following) for control systems where these devices are operating.
• Devices should not end up exposed to public networks without the use of virtual private networks (VPNs) for remote access.
• Users should use firewalls for network segmentation or controller isolation.
• Available communication channels or ports not needed in the application should be turned off. Administrators and users should check whether the application offers any option of deactivating active communication channels (e.g., SNMP, FTP, BootP, DCP), or setting passwords to prevent third parties from unauthorized accessing the controller and modifying the system.
• Access to the devices should be limited to the fewest possible authorized personnel.
• Change standard or default passwords when first installing every component. Passwords should be changed in regular interval in order to reduce risks of becoming public. Passwords should have a maximum strength by the use of small and capital letters as well as numbers and special characters with a length of at least 10 characters.
• Conduct regular thread analyses to discover whether current measures meet the safety requirements.
• Install and maintain security software in order to defend new or recurring risks; such as viruses, Trojans, phishing attacks.
Users may decide to use the ILC 1×1 PLCs with the latest Firmware 4.42, because it offers the HTTPS protocol and HTML5 for the web server-based HMI system.
With regard to the controller’s communication interfaces, Phoenix Contact recommends not to use the ILC 1xx controller in safety-critical applications unless using additional security devices.
For more information on this vulnerability and the associated update and mitigation strategies, email Phoenix Contact.