This afternoon the DHS ICS-CERT published a fourth update to a Siemens HMI advisory originally published in April and most recently updated last month. Additionally a new advisory was published for multiple buffer overflow vulnerabilities in multiple Yokogawa products.
This update clarifies that the man-in-the-middle vulnerability does not apply to the Simatics PCS 7 products. There is not an update to the Siemens Security Advisory since the August update and there has never been a mention of the ‘Simatics PCS 7’ in their versions of this advisory.
This advisory describes multiple stack-based buffer vulnerabilities in network communications function of a large number of Yokogawa products. The vulnerabilities are apparently being self-reported by Yokogawa. Yokogawa reports that the “vulnerability will be remediated with the latest release of all of the affected products, some of which are already publicly available” [emphasis added].
ICS-CERT reports that a relatively low skilled attacker could remotely exploit these vulnerabilities to either make the network communications unresponsive or unavailable, or to execute arbitrary code. Yokogawa reports that if the affected products are on isolated networks that the risk of exploiting the vulnerability is low.
Neither ICS-CERT or Yokogawa have provided a list of products that the current version provides mitigation for the vulnerability.