Siemens has released software updates for some of its industrial products, including SIMATIC and SCALANCE, to patch several medium severity denial-of-service (DoS) vulnerabilities.
Siemens and ICS-CERT have each published three advisories covering a total of four security holes. Two of the advisories describe vulnerabilities affecting products that use the PROFINET Discovery and Configuration Protocol (DCP).
The flaws, caused by improper input validation, can be exploited by attackers with network access to cause a DoS condition on devices by sending specially crafted PROFINET DCP broadcast packets. Manual intervention is required to restore the system after an attack.
The list of affected products includes SIMATIC communication processors, modules, PLCs, identification systems, HMI panels, and remote servicing products; SCALANCE routers, switches and firewalls; SITOP power supply units; and SIRIUS relays. Some SIMOCODE, SINAMICS, SIMOTION, SINEMA, SINAUT, and SINUMERIK products are also impacted.
Duan JinTong, Ma ShaoShuai and Cheng Lei from the NSFOCUS Security Team reported these flaws to Siemens. The vendor has released patches for some of the affected products, and provided mitigation recommendations for products that have yet to receive fixes.
Siemens’ recommendations include using VPNs to protect network communications, and applying cell protection and defense-in-depth concepts as described in the company’s operational guidelines for industrial security.
The third advisory published by Siemens and ICS-CERT describes a DoS vulnerability affecting SIMATIC WinCC SCADA systems, the WinCC Runtime Professional visualization platform, and the WinCC (TIA Portal) Professional engineering software.
The weakness, reported by researchers at Kaspersky Lab, allows an attacker to crash services by sending specially crafted messages to the DCOM interface. This flaw is less severe as the attack requires not only network access, but also administrative credentials.
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