Siemens’ May 2021 Patch Tuesday advisories address roughly 60 vulnerabilities introduced by the use of third-party components.
The German industrial giant has released more than a dozen advisories to inform customers about tens of vulnerabilities affecting RUGGEDCOM, SCALANCE, SIMATIC, SINEMA, SINAMICS and other products. The company has advised organizations using its products to either install updates or apply workarounds and mitigations to reduce the risk of exploitation.
Of the 14 advisories published this week, nine cover 60 vulnerabilities related to third-party components. The remaining advisories cover only 7 flaws that are specific to Siemens products.
The advisories related to third-party software address the “SAD DNS” cache poisoning vulnerability in the Linux kernel, tens of vulnerabilities in the UltraVNC and SmartVNC remote access tools, two issues in Mendix modules, six issues affecting industrial PCs and other devices powered by Intel CPUs, and 19 vulnerabilities in Aruba Instant Access Point (IAP).
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The security holes, many of which have been classified as critical and high severity, can be exploited for information disclosure, DoS attacks and remote code execution.
The issues specific to Siemens products are related to how SCALANCE devices handle OSPF packets (DoS), how the Tecnomatix Plant Simulation product handles SPP files (DoS, code execution, data extraction), and how SIMATIC NET CP devices handle specially crafted TCP packets (DoS).
Other advisories describe a DoS vulnerability that can be exploited without authentication against SIMATIC HMI products, and a Telnet authentication issue that can be used to gain full remote access to some SIMATIC HMI panels.
Related: Siemens Releases Several Advisories for ‘NAME:WRECK’ Vulnerabilities
Related: Siemens Releases Several Advisories for Vulnerabilities in Third-Party Components
Related: Tens of Vulnerabilities in Siemens PLM Products Allow Code Execution
Related: Siemens Patches 21 More File Parsing Vulnerabilities in PLM Products

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.
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