# CVE-2021-31890

## Summary

- **CVE ID:** CVE-2021-31890
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-240
- **Published:** Nov 9, 2021
- **Last Modified:** Mar 13, 2026

## 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), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), SIMOTICS CONNECT 400 (All versions < V1.0.0.0). The total length of an TCP 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-2021-0017)

## Affected Products

- Siemens — Capital Embedded AR Classic 431-422 (0)
- Siemens — Capital Embedded AR Classic R20-11 (0)
- Siemens — PLUSCONTROL 1st Gen (All versions)
- Siemens — SIMOTICS CONNECT 400 (All versions < V0.5.0.0)
- Siemens — SIMOTICS CONNECT 400 (All versions < V1.0.0.0)

## References

- [CNA](https://cert-portal.siemens.com/productcert/pdf/ssa-114589.pdf)
- [CNA](https://cert-portal.siemens.com/productcert/pdf/ssa-044112.pdf)
- [CNA](https://cert-portal.siemens.com/productcert/pdf/ssa-620288.pdf)
- [CNA](https://cert-portal.siemens.com/productcert/pdf/ssa-845392.pdf)
- [CNA](https://cert-portal.siemens.com/productcert/pdf/ssa-223353.pdf)
- [CNA](https://cert-portal.siemens.com/productcert/html/ssa-114589.html)
- [CNA](https://cert-portal.siemens.com/productcert/html/ssa-044112.html)
- [CNA](https://cert-portal.siemens.com/productcert/html/ssa-620288.html)
- [CNA](https://cert-portal.siemens.com/productcert/html/ssa-845392.html)
- [CNA](https://cert-portal.siemens.com/productcert/html/ssa-223353.html)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 2.50%
- **EPSS Percentile:** 85.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._