Siemens has new firmware to clear up a resource exhaustion vulnerability in its 7KM PAC Switched Ethernet product, according to a report with ICS-CERT.
All versions prior to V2.1.3 of the 7KM PAC Switched Ethernet PROFINET expansion module suffer from the issue.
Successful exploitation of this vulnerability could cause a denial-of-service condition in the affected component that may require a manual restart of the main device to recover.
Siemens reported this vulnerability and released an advisory with firmware update information.
No known public exploits specifically target this vulnerability. This vulnerability is not remotely exploitable. However, an attacker with low skill level could leverage the vulnerability.
A denial-of-service condition could be induced by a specially crafted PROFINET DCP packet sent as a local Ethernet (Layer 2) broadcast. The affected component requires a manual restart via the main device to recover.
CVE-2017-9945 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 4.3.
The product mainly sees use in the energy sector and it is also use on a global basis.
Siemens provides firmware Version V2.1.3  for 7KM PAC Switched Ethernet PROFINET expansion modules, which fixes the vulnerability, and recommends users to update to the new fixed version. Click here for the new firmware update.
Siemens recommends users protect network access with appropriate mechanisms such as firewalls, segmentation, and VPNs. Siemens also advises that users configure the operational environment according to Siemens’ Operational Guidelines for Industrial Security.
For more information on this vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-771218.