Virtual Event Today: Supply Chain Security Summit - Join Event In-Progress

Security Experts:

Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

ICS/OT

Siemens SCALANCE X Switches Vulnerable to DoS Attacks

Siemens on Tuesday released several new advisories describing vulnerabilities in the company’s products, including an unpatched denial-of-service (DoS) flaw affecting SCALANCE X industrial switches.

Siemens on Tuesday released several new advisories describing vulnerabilities in the company’s products, including an unpatched denial-of-service (DoS) flaw affecting SCALANCE X industrial switches.

According to advisories published by Siemens and the DHS’s Cybersecurity and Infrastructure Security Agency (CISA), SCALANCE X-200 switches are affected by a security hole that allows an unauthenticated attacker to cause a device to enter a DoS condition by repeatedly sending large message packets to the Telnet service.

The vulnerability was reported to Siemens by industrial cybersecurity firm Nozomi Networks.Siemens SCALANCE X switch vulnerabilities

“The vulnerability affects the telnet server, allowing an attacker to crash the service by sending a large number of packets on the port 23/TCP,” Andrea Carcano, CPO and co-founder of Nozomi Networks, told SecurityWeek. “After the crash, the device is automatically restarted, disconnecting from the network all the connected devices; this can lead to a potential process disruption.”

While exploitation of this vulnerability would require access to the network housing the targeted switches, Carcano said Nozomi’s intelligence team has identified a couple of devices that may be exposed to attacks launched directly from the internet.

As for how difficult it is to exploit this vulnerability, Carcano noted, “The attacker does not need any understanding about specific protocols or systems, just some knowledge of the standard telnet protocol.” However, he said, “The vulnerability is not easy to exploit as it could have a non-deterministic replication step to take in order to trigger it.”

Siemens has yet to release any patches for the vulnerability, which it has classified as “high severity,” but the company has informed customers that they can prevent potential attacks by disabling the Telnet service on affected devices (using SSH instead is recommended), and restricting network access to TCP port 23.

Learn More About Flaws in ICS Products at SecurityWeek’s 2019 ICS Cyber Security Conference

The German industrial giant also informed customers on Tuesday that its SCALANCE X switches and SCALANCE SC firewalls are affected by two medium-severity flaws that can be exploited for DoS attacks and arbitrary command execution. However, exploitation requires authentication and, for one of the vulnerabilities, physical access to the targeted device.

Siemens has also published an advisory in response to a Black Hat presentation describing how rogue engineering stations can be used to take control of some S7 programmable logic controllers (PLCs).

Finally, Siemens released an advisory describing a high-severity DoS vulnerability impacting the web server of SINAMICS converters. The flaw allows an attacker with network access to the affected system to cause a DoS condition without the need for authentication or user interaction.

Related: Siemens Teams With Chronicle on Cybersecurity Solutions for Energy Industry

Related: Siemens Patches Serious DoS Flaws in Many Industrial Products

Written By

Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join this webinar to learn best practices that organizations can use to improve both their resilience to new threats and their response times to incidents.

Register

Join this live webinar as we explore the potential security threats that can arise when third parties are granted access to a sensitive data or systems.

Register

Expert Insights

Related Content

Vulnerabilities

Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...

Application Security

Drupal released updates that resolve four vulnerabilities in Drupal core and three plugins.

Vulnerabilities

Apple has released updates for macOS, iOS and Safari and they all include a WebKit patch for a zero-day vulnerability tracked as CVE-2023-23529.

Cloud Security

VMware vRealize Log Insight vulnerability allows an unauthenticated attacker to take full control of a target system.

Application Security

A CSRF vulnerability in the source control management (SCM) service Kudu could be exploited to achieve remote code execution in multiple Azure services.

IoT Security

Lexmark warns of a remote code execution (RCE) vulnerability impacting over 120 printer models, for which PoC code has been published.

CISO Strategy

Cybersecurity-related risk is a top concern, so boards need to know they have the proper oversight in place. Even as first-timers, successful CISOs make...