CVE-2021-31346: Siemens Apogee Modular Building Controller Firmware

Critical severity, CVSS 9.1. EPSS: 2% chance of exploitation in the next 30 days.

A vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions < V2303), PLUSCONTROL 1st Gen (All versions), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), SIMOTICS CONNECT 400 (All versions < V1.0.0.0). The total length of an ICMP payload (set in the IP header) is unchecked. This may lead to various side effects, including Information Leak and Denial-of-Service conditions, depending on the network buffer organization in memory. (FSMD-2021-0007)

Affected products

• Siemens Apogee Modular Building Controller Firmware: any version
• Siemens Apogee Modular Equiment Controller Firmware: any version
• Siemens Apogee Pxc Compact Firmware: any version
• Siemens Apogee Pxc Modular Firmware: any version
• Siemens Capital Vstar: any version
• Siemens Nucleus Net: any version
• Siemens Nucleus Readystart v3: before 2017.02.1 (fixed in 2017.02.1)
• Siemens Nucleus Readystart v4: before 4.1.1 (fixed in 4.1.1)
• Siemens Nucleus Source Code: any version
• Siemens Talon Tc Compact Firmware: any version
• Siemens Talon Tc Modular Firmware: any version

Published 2021-11-09. Last modified 2026-06-17.