SCALANCE XM-400 and XR-500 devices contain a vulnerability in the OSPF protocol implementation that could allow an unauthenticated remote attacker to create a permanent denial-of-service condition.
As a general security measure, Siemens strongly recommends to protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends to configure the environment according to Siemens’ operational guidelines for Industrial Security (Download: https://www.siemens.com/cert/operational-guidelines-industrial-security), and to follow the recommendations in the product manuals.
An additional classification has been performed using the CWE classification, a community-developed list of common software security weaknesses. This serves as a common language and as a baseline for weakness identification, mitigation, and prevention efforts. A detailed list of CWE classes can be found at: https://cwe.mitre.org/.
The OSPF protocol implementation in affected devices incorrectly handles the number of LSA fields in combination with other modified fields.
All SCALANCE XM-400 and XR-500 devices are affected, including those who do not support layer 3 routing and OSPF natively, as the activation of these features is possible via the KEY-PLUG modules: