Rewterz Threat Advisory – ICS: Siemens SCALANCE and SIMATIC Denial of Service Vulnerability

Severity

Medium

Analysis Summary

A resource exhaustion vulnerability has been identified in scalance and simatic products of Siemens. The vulnerability is remotely exploitable and requires low skill to exploit. The VxWorks-based Profinet TCP stack can be forced to make resource-intense calls for every incoming packet, which can lead to a denial-of-service condition.

CVE-2019-19301 has been assigned to this vulnerability.

Impact

• Resource Exhaustion
• Denial of Service

Affected Vendors

Siemens

Affected Products

• SCALANCE X-200 switch family (incl. SIPLUS NET variants): all versions
• SCALANCE X-200IRT switch family (incl. SIPLUS NET variants): all versions
• SCALANCE X-300 switch family (incl. X408 and SIPLUS NET variants): all versions
• SIMATIC CP 443-1 (incl. SIPLUS NET variants): all versions
• SIMATIC CP 443-1 Advanced (incl. SIPLUS NET variants): all versions
• SIMATIC RF180C: all versions
• SIMATIC RF182C: all versions

Remediation

• Updates are not yet available.
• Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
• When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), updated to the most current version available.