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Vulnerability record · CVE-2021-31889 · published 9 November 2021

CVE-2021-31889: Siemens capital vstar vulnerability

Siemens · Capital Vstar

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). Malformed TCP packets with a corrupted SACK option leads to Information Leaks and Denial-of-Service conditions. (FSMD-2021-0015)

9.1 CVSS 3.1 Critical EPSS 2.2% · top 18.4% CWE-191 · CWE-191
9.1CVSS 3.1 base score, v2 6.4
2.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
10Affected product versions listed by NVD
15References
17 Jun 2026Last modified by NVD

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). Malformed TCP packets with a corrupted SACK option leads to Information Leaks and Denial-of-Service conditions. (FSMD-2021-0015)

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

Affected products

10 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://cert-portal.siemens.com/productcert/html/ssa-044112.html
https://cert-portal.siemens.com/productcert/html/ssa-114589.html
https://cert-portal.siemens.com/productcert/html/ssa-223353.html
https://cert-portal.siemens.com/productcert/html/ssa-620288.html
https://cert-portal.siemens.com/productcert/html/ssa-845392.html
https://cert-portal.siemens.com/productcert/pdf/ssa-044112.pdf Vendor Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-114589.pdf Vendor Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-223353.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-620288.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-845392.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-044112.pdf Vendor Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-114589.pdf Vendor Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-223353.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-620288.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-845392.pdf

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2021-31884Siemens capital vstar vulnerabilityA vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BAC…EPSS 1.5%9.8CVE-2021-31886Siemens nucleus net out-of-bounds write vulnerabilityA vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BAC…EPSS 3.0%9.1CVE-2021-31345Siemens capital vstar vulnerabilityA vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions < V2303),…EPSS 1.6%9.1CVE-2021-31346Siemens capital vstar vulnerabilityA vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions < V2303),…EPSS 2.0%9.1CVE-2021-31890Siemens capital vstar vulnerabilityA vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions < V2303),…EPSS 2.2%8.8CVE-2021-31887Siemens nucleus net out-of-bounds write vulnerabilityA vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BAC…EPSS 2.4%8.8CVE-2021-31888Siemens nucleus net out-of-bounds write vulnerabilityA vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BAC…EPSS 2.4%8.7CVE-2022-38371Siemens nucleus net uncontrolled resource consumption vulnerabilityA vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BAC…EPSS 1.4%

Source: NIST National Vulnerability Database (record CVE-2021-31889), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.