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Fencer Intel
high 7.5

CVE-2021-31885 json

A vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC…

published 5y ago modified 4mo ago also EUVD-2021-18760

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 69%
public exploits
0
none known

Summary

A vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BACnet) (All versions), APOGEE MEC (PPC) (P2 Ethernet) (All versions), APOGEE PXC Compact (BACnet) (All versions < V3.5.4), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.19), APOGEE PXC Modular (BACnet) (All versions < V3.5.4), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.19), Desigo PXC00-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC00-U (All versions >= V2.3 and < V6.30.016), Desigo PXC001-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC100-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC12-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC128-U (All versions >= V2.3 and < V6.30.016), Desigo PXC200-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC22-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC22.1-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC36.1-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC50-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC64-U (All versions >= V2.3 and < V6.30.016), Desigo PXM20-E (All versions >= V2.3 and < V6.30.016), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.4), Nucleus ReadyStart V4 (All versions < V4.1.1), Nucleus Source Code (All versions), PLUSCONTROL 1st Gen (All versions), TALON TC Compact (BACnet) (All versions < V3.5.4), TALON TC Modular (BACnet) (All versions < V3.5.4). TFTP server application allows for reading the contents of the TFTP memory buffer via sending malformed TFTP commands. (FSMD-2021-0009)

Patch / fix

  • siemens nucleus_readystart_v3 2017.02.4
  • siemens nucleus_readystart_v4 4.1.1

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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 ReadyStart V4 <V4.1.1
    affected: fixed in V4.1.1 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-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

1.24% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • Siemens APOGEE MBC (PPC) (BACnet)
  • Siemens APOGEE MBC (PPC) (P2 Ethernet)
  • Siemens APOGEE MEC (PPC) (BACnet)
  • Siemens APOGEE MEC (PPC) (P2 Ethernet)
  • Siemens APOGEE PXC Compact (BACnet)
  • Siemens APOGEE PXC Compact (P2 Ethernet)
  • Siemens APOGEE PXC Modular (BACnet)
  • Siemens APOGEE PXC Modular (P2 Ethernet)
  • Siemens Desigo PXC00-E.D
  • Siemens Desigo PXC00-U
  • Siemens Desigo PXC001-E.D
  • Siemens Desigo PXC100-E.D
  • Siemens Desigo PXC12-E.D
  • Siemens Desigo PXC128-U
  • Siemens Desigo PXC200-E.D
  • Siemens Desigo PXC22-E.D
  • Siemens Desigo PXC22.1-E.D
  • Siemens Desigo PXC36.1-E.D
  • Siemens Desigo PXC50-E.D
  • Siemens Desigo PXC64-U
  • Siemens Desigo PXM20-E
  • Siemens Nucleus NET
  • Siemens Nucleus ReadyStart V3
  • Siemens Nucleus ReadyStart V4
  • Siemens Nucleus Source Code
  • Siemens PLUSCONTROL 1st Gen
  • Siemens TALON TC Compact (BACnet)
  • Siemens TALON TC Modular (BACnet)

Classification

Weakness
  • CWE-805 Buffer Access with Incorrect Length Value

References

Sources

Fencer Intel 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.