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Fencer Vulns
high 7.5

CVE-2021-31345 json

A vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions…

published 2021-11-09 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18255

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

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)

Patch / fix

  • Siemens Capital Embedded AR Classic R20-11 V2303

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-313-03 updated cvss 7.5

Siemens Nucleus RTOS TCP/IP Stack

  • Siemens Nucleus NET
    affected: mitigation, no fix planned
  • Siemens Nucleus ReadyStart V3 <V2017.02.4
    affected: fixed in V2017.02.4 support.sw.siemens.com
  • Siemens Nucleus Source Code
    affected: vendor fix

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-21-315-07 updated cvss 7.5

Siemens Nucleus RTOS-based APOGEE and TALON Products (Update C)

  • Siemens APOGEE MBC (PPC) (BACnet) Siemens APOGEE MBC (PPC) (P2 Ethernet) Siemens APOGEE MEC (PPC) (BACnet) Siemens APOGEE MEC (PPC) (P2 Ethernet)
    affected: mitigation, no fix planned
  • Siemens APOGEE PXC Compact (BACnet) <V3.5.4
    affected: fixed in V3.5.4, mitigation
  • Siemens APOGEE PXC Compact (P2 Ethernet) <V2.8.19
    affected: fixed in V2.8.19, mitigation
  • Siemens APOGEE PXC Modular (BACnet) <V3.5.4
    affected: fixed in V3.5.4, mitigation
  • Siemens APOGEE PXC Modular (P2 Ethernet) <V2.8.19
    affected: fixed in V2.8.19, mitigation
  • Siemens Desigo PXC00-E.D >=V2.3_and_<V6.30.016 Siemens Desigo PXC00-U >=V2.3_and_<V6.30.016 Siemens Desigo PXC001-E.D >=V2.3_and_<V6.30.016 Siemens Desigo PXC12-E.D >=V2.3_and_<V6.30.016 Siemens Desigo PXC22-E.D >=V2.3_and_<V6.30.016 Siemens Desigo PXC22.1-E.D >=V2.3_and_<V6.30.016
    +7 more products
    Siemens Desigo PXC36.1-E.D >=V2.3_and_<V6.30.016 Siemens Desigo PXC50-E.D >=V2.3_and_<V6.30.016 Siemens Desigo PXC64-U >=V2.3_and_<V6.30.016 Siemens Desigo PXC100-E.D >=V2.3_and_<V6.30.016 Siemens Desigo PXC128-U >=V2.3_and_<V6.30.016 Siemens Desigo PXC200-E.D >=V2.3_and_<V6.30.016 Siemens Desigo PXM20-E >=V2.3_and_<V6.30.016
    affected: fixed in V6.30.016, mitigation support.industry.siemens.com
  • Siemens TALON TC Compact (BACnet) <V3.5.4 Siemens TALON TC Modular (BACnet) <V3.5.4
    affected: fixed in V3.5.4, mitigation

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-21-350-06 updated cvss 7.5

Siemens Capital VSTAR

  • Siemens Capital Embedded AR Classic 431-422
    affected: mitigation, no fix planned
  • Siemens Capital Embedded AR Classic R20-11 <V2303
    affected: fixed in V2303, mitigation

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-22-013-03 updated cvss 7.5

Siemens Energy PLUSCONTROL

  • Siemens PLUSCONTROL 1st Gen
    affected: mitigation, no fix planned

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

1.63% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
NVD 2.0 6.4 AV:N/AC:L/Au:N/C:P/I:N/A:P

Affected products

  • Siemens Capital Embedded AR Classic 431-422
  • Siemens Capital Embedded AR Classic R20-11
  • Siemens PLUSCONTROL 1st Gen

Classification

Weakness
  • CWE-1284 Improper Validation of Specified Quantity in Input

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.