Is CVE-2021-31884 actively exploited?

No active exploitation of CVE-2021-31884 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-31884 be exploited remotely?

Yes. CVE-2021-31884 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-31884?

CVE-2021-31884 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-31884

CRITICAL

CVE-2021-31884

CWE-170Published: November 9, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

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), Capital VSTAR (All versions with enabled Ethernet options), 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 Source Code (All versions), TALON TC Compact (BACnet) (All versions < V3.5.4), TALON TC Modular (BACnet) (All versions < V3.5.4). The DHCP client application assumes that the data supplied with the “Hostname” DHCP option is NULL terminated. In cases when global hostname variable is not defined, this may lead to Out-of-bound reads, writes, and Denial-of-service conditions. (FSMD-2021-0014)

NVD Source

Technical Analysis

CVE-2021-31884 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected Vendors & Products

siemens42 product(s)

capital vstarnucleus netnucleus readystart v3nucleus source codeapogee modular building controller firmwareapogee modular building controllerapogee modular equiment controller firmwareapogee modular equiment controllerapogee pxc compact firmwareapogee pxc compactapogee pxc modular firmwareapogee pxc modular+30

Source: NVD CPE · 42 total CPE entries