# Improper null termination in Siemens APOGEE MBC (PPC) (BACnet) and others CVE record · `CVE-2021-31887` - **Identifiers:** `CVE-2021-31887` - **State:** Confirmed - **Severity:** No CVSS score - **Critical:** No - **CNA:** siemens - **Weakness (CWE):** [CWE-170](https://cwe.mitre.org/data/definitions/170.html) - **Tags:** [CWE-170](https://agentprime.io/advisories/tag/cwe-170.md) - **Technologies:** [Siemens APOGEE MBC (PPC) (BACnet)](https://agentprime.io/advisories/technology/siemens-apogee-mbc-ppc-bacnet.md) · [Siemens APOGEE MBC (PPC) (P2 Ethernet)](https://agentprime.io/advisories/technology/siemens-apogee-mbc-ppc-p2-ethernet.md) · [Siemens APOGEE MEC (PPC) (BACnet)](https://agentprime.io/advisories/technology/siemens-apogee-mec-ppc-bacnet.md) · [Siemens APOGEE MEC (PPC) (P2 Ethernet)](https://agentprime.io/advisories/technology/siemens-apogee-mec-ppc-p2-ethernet.md) · [Siemens APOGEE PXC Compact (BACnet)](https://agentprime.io/advisories/technology/siemens-apogee-pxc-compact-bacnet.md) · [Siemens APOGEE PXC Compact (P2 Ethernet)](https://agentprime.io/advisories/technology/siemens-apogee-pxc-compact-p2-ethernet.md) · [Siemens APOGEE PXC Modular (BACnet)](https://agentprime.io/advisories/technology/siemens-apogee-pxc-modular-bacnet.md) · [Siemens APOGEE PXC Modular (P2 Ethernet)](https://agentprime.io/advisories/technology/siemens-apogee-pxc-modular-p2-ethernet.md) · [Siemens Desigo PXC00-E.D](https://agentprime.io/advisories/technology/siemens-desigo-pxc00-e-d.md) · [Siemens Desigo PXC00-U](https://agentprime.io/advisories/technology/siemens-desigo-pxc00-u.md) · [Siemens Desigo PXC001-E.D](https://agentprime.io/advisories/technology/siemens-desigo-pxc001-e-d.md) · [Siemens Desigo PXC100-E.D](https://agentprime.io/advisories/technology/siemens-desigo-pxc100-e-d.md) · [Siemens Desigo PXC12-E.D](https://agentprime.io/advisories/technology/siemens-desigo-pxc12-e-d.md) · [Siemens Desigo PXC128-U](https://agentprime.io/advisories/technology/siemens-desigo-pxc128-u.md) · [Siemens Desigo PXC200-E.D](https://agentprime.io/advisories/technology/siemens-desigo-pxc200-e-d.md) · [Siemens Desigo PXC22-E.D](https://agentprime.io/advisories/technology/siemens-desigo-pxc22-e-d.md) · [Siemens Desigo PXC22.1-E.D](https://agentprime.io/advisories/technology/siemens-desigo-pxc22-1-e-d.md) · [Siemens Desigo PXC36.1-E.D](https://agentprime.io/advisories/technology/siemens-desigo-pxc36-1-e-d.md) · [Siemens Desigo PXC50-E.D](https://agentprime.io/advisories/technology/siemens-desigo-pxc50-e-d.md) · [Siemens Desigo PXC64-U](https://agentprime.io/advisories/technology/siemens-desigo-pxc64-u.md) - **Published:** 9 Nov 2021 - **Updated:** 3 Aug 2024 - **Reviewed by a person:** No Published by the CVE Program (CNA: siemens) at 9 Nov 2021, 11:32 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. ## Affected products, as the CNA wrote them - Vendor: Siemens. Product: APOGEE MBC (PPC) (BACnet). - affected: `All versions` - Vendor: Siemens. Product: APOGEE MBC (PPC) (P2 Ethernet). - affected: `All versions` - Vendor: Siemens. Product: APOGEE MEC (PPC) (BACnet). - affected: `All versions` - Vendor: Siemens. Product: APOGEE MEC (PPC) (P2 Ethernet). - affected: `All versions` - Vendor: Siemens. Product: APOGEE PXC Compact (BACnet). - affected: `All versions < V3.5.4` - Vendor: Siemens. Product: APOGEE PXC Compact (P2 Ethernet). - affected: `All versions < V2.8.19` - Vendor: Siemens. Product: APOGEE PXC Modular (BACnet). - affected: `All versions < V3.5.4` - Vendor: Siemens. Product: APOGEE PXC Modular (P2 Ethernet). - affected: `All versions < V2.8.19` - Vendor: Siemens. Product: Desigo PXC00-E.D. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC00-U. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC001-E.D. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC100-E.D. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC12-E.D. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC128-U. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC200-E.D. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC22-E.D. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC22.1-E.D. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC36.1-E.D. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC50-E.D. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXC64-U. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Desigo PXM20-E. - affected: `All versions >= V2.3 and < V6.30.016` - Vendor: Siemens. Product: Nucleus NET. - affected: `All versions` - Vendor: Siemens. Product: Nucleus ReadyStart V3. - affected: `All versions < V2017.02.4` - Vendor: Siemens. Product: Nucleus Source Code. - affected: `All versions` - Vendor: Siemens. Product: TALON TC Compact (BACnet). - affected: `All versions < V3.5.4` - Vendor: Siemens. Product: TALON TC Modular (BACnet). - affected: `All versions < V3.5.4` ## Not analysed yet We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter. ## Severity and exploitation No source has published a CVSS score for this record yet. - **CISA KEV:** Not listed. - **EPSS:** 0.024, the 84th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline This record came from the full history of the CVE Program, published 9 Nov 2021. New records show when each source confirmed them. ## Sources - [CVE List: CVE-2021-31887](https://www.cve.org/CVERecord?id=CVE-2021-31887) - [NVD: CVE-2021-31887](https://nvd.nist.gov/vuln/detail/CVE-2021-31887) ### References from the CNA - - Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description. ## Check whether this affects you This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run. - With the agentprime MCP server (), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: - As JSON: - Everything that needs attention now: --- The web page: . Everything for agents: .