Siemens has a workaround and mitigation to handle an expected behavior violation in its SCALANCE X, according to a report with NCCIC, which is now reporting on the vulnerability after Siemens ProductCERT released the information two weeks ago.
Successful exploitation of this remotely exploitable vulnerability, which Siemens self-reported, could allow an attacker to feed data over a mirror port and into the mirrored network.
The following SCALANCE products suffer from the issue:
• SCALANCE X-200, all versions
• SCALANCE X-300, all versions
• SCALANCE XP/XC/XF-200, all versions older than v4.1
The monitor barrier of the affected products insufficiently blocks data from being forwarded over the mirror port and into the mirrored network. An attacker could exploit this vulnerability to transmit malicious packets to systems in the mirrored network to influence their configuration and runtime behavior.
This vulnerability could be exploited by an attacker with network access to the traffic-receiving network. Successful exploitation requires no system privileges and no user interaction. An attacker could use the vulnerability to compromise the confidentiality and availability of the traffic-generating network.
CVE-2019-6569 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 5.4.
The product sees use mainly in the chemical, critical manufacturing, energy, food and agriculture, and water and wastewater systems sectors. It also sees action on a global basis.
This vulnerability requires high skill level to exploit. No known public exploits specifically target this vulnerability.
Siemens identified the following specific workaround/mitigation that users can implement to reduce the risk associated with this vulnerability in SCALANCE XP/XC/XF-200.
• Update to v4.1
Until a software update can be installed, Siemens recommends users apply defense in depth principles, ensuring no devices that transmit data back in the mirroring network are operated within the mirrored network.
As a general security measure, Siemens recommends users protect network access to devices with appropriate mechanisms. To operate devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens’ operational guidelines for industrial security and following the product manual recommendations.
Click here for additional information on industrial security by Siemens.
For additional information see Siemens’ security advisory SSA-557804.