Siemens Patches Ethernet Switch Security Vulnerabilities

Siemens has patched two critical security flaws in its Ethernet switches uncovered by researchers with IOActive.

The vulnerabilities existed in Siemens’ SCALANCE X-200 Switch Family, which are used to connect industrial control system components such as programmable logic controllers (PLCs) and human machine interfaces (HMIs). According to Siemens, the switches offer a Web interface that allows users to change the configuration using a common Web browser.

The first vulnerability is CVE-2013-5709, and can be used to enable an attacker to hijack web sessions over the network without authentication. This is due to insufficient entropy in the random number generator used by vulnerable versions of the product, Siemens stated in an advisory.

The second vulnerability – CVE-2013-5944 – resides in the integrated web server of SCALANCE X-200 switches and could allow attackers to perform administrative operations over the network. This too can be done without authentication.

Siemens described the vulnerabilities in advisories here and here.

“Siemens ProductCERT were professional, courteous, and did not adopt an adversarial attitude when I contacted them about the vulnerabilities,” said Eireann Leverett, senior security consultant for IOActive in a statement. “Consequently, we were able to clarify the vulnerabilities quickly, and they produced a patch within three months.”

Leverett is slated to demonstrate the vulnerabilities and release code organizations can use to check their own devices at the S4 conference next week in Miami.

Siemens advises customers to apply the relevant firmware updates or upgrade.