CVE-2021-31345: A vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions < V2303), ...

Description

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). The total length of an UDP 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 a user-defined applications that runs on top of the UDP protocol. (FSMD-2021-0006)

Metrics

CVSS 3.1

9.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS Probability

1.58%

72.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-1284

Affected Software

Vendor	Product	Versions
Siemens	Capital Vstar	All versions
Siemens	Nucleus Net	All versions
Siemens	Nucleus Readystart V3	< 2014.12
Siemens	Nucleus Source Code	All versions
Siemens	Apogee Modular Building Controller Firmware	All versions
Siemens	Apogee Modular Equiment Controller Firmware	All versions
Siemens	Apogee Pxc Compact Firmware	All versions
Siemens	Apogee Pxc Modular Firmware	All versions
Siemens	Talon Tc Compact Firmware	All versions
Siemens	Talon Tc Modular Firmware	All versions

References

Timeline

Published: Nov 9, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31345?

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). The total length of an UDP 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 a user-defined applications that runs on top of the UDP protocol. (FSMD-2021-0006)

How severe is CVE-2021-31345?

CVE-2021-31345 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 1.58% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31345?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.