High-severity flaw opens Siemens Industrial Switches to attacks

Siemens has started releasing security patches to fix a high severity access control vulnerability in its industrial switches tracked as CVE-2017-12736.

The flaw was discovered by experts at Siemens and could be exploited by remote attackers to hack some of Siemens industrial communications devices.

The vulnerability affects SCALANCE X industrial Ethernet switches, and Ruggedcom switches and serial-to-ethernet devices running the Rugged Operating System (ROS).

The flaw resides in the Ruggedcom Discovery Protocol (RCDP), which allows the Ruggedcom Explorer management tool to discover and configure ROS-based devices.

According to Siemens, the RCDP is not configured properly after a device is commissioned, this allows an unauthenticated attacker who has access to the network to remotely perform administrative actions.

“RUGGEDCOM switches and serial-to-Ethernet devices are used to connect devices that
operate in harsh environments such as electric utility substations and traffic control cabinets.
SCALANCE X switches are used to connect industrial components like Programmable Logic
Controllers (PLCs) or Human Machine Interfaces (HMIs). ” states the security advisory published by Siemens.

“After initial configuration, the RCDP is still able to write to the device under certain conditions, potentially allowing users located in the adjacent network of the targeted device to perform unauthorized administrative actions,”

Siemens has rolled out the release of ROS 5.0.1 to fix the issue in Ruggedcom RSL910 devices and the version 4.3.4 to address the flaw in other ROS-based devices.

An update has also been rolled out for Ruggedcom Explorer.

Siemens hasn’t released security updates for SCALANCE XB-200, XC-200, XP-200, XR300-WG, XR-500 and XM-400 switches, users can mitigate possible attacks by manually disabling RCDP.

The ICS-CERT published a security advisory that includes NCCIC/ICS-CERT recommendations to minimize the risk of exploitation of the vulnerabilities.

Specifically, users should:

Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.

[adrotate banner=”9″]	[adrotate banner=”12″]

Pierluigi Paganini

(Security Affairs – Siemens Industrial Switches, hacking)

[adrotate banner=”5″]

[adrotate banner=”13″]

Pierluigi Paganini

Pierluigi Paganini is member of the ENISA (European Union Agency for Network and Information Security) Threat Landscape Stakeholder Group and Cyber G7 Group, he is also a Security Evangelist, Security Analyst and Freelance Writer. Editor-in-Chief at "Cyber Defense Magazine", Pierluigi is a cyber security expert with over 20 years experience in the field, he is Certified Ethical Hacker at EC Council in London. The passion for writing and a strong belief that security is founded on sharing and awareness led Pierluigi to find the security blog "Security Affairs" recently named a Top National Security Resource for US. Pierluigi is a member of the "The Hacker News" team and he is a writer for some major publications in the field such as Cyber War Zone, ICTTF, Infosec Island, Infosec Institute, The Hacker News Magazine and for many other Security magazines. Author of the Books "The Deep Dark Web" and “Digital Virtual Currency and Bitcoin”.