CVE-2019-13939

Service disruption via invalid DHCP address assignment

Published Jan 16, 2020 · Updated Jun 10, 2025

Improper input validation in Siemens Nucleus NET-based products allows adjacent attackers to set an invalid IP address through DHCP packets. The enabled DHCP client accepts specially crafted DHCP input and applies an invalid address instead of rejecting the malformed value. DHCP must be enabled; it is disabled by default on APOGEE, Desigo, and TALON devices, while successful exploitation disrupts network service and alters addressing.

CVSS severity7.1
High
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper input validation in Siemens Nucleus NET-based products allows adjacent attackers to set an invalid IP address through DHCP packets. The enabled DHCP client accepts specially crafted DHCP input and applies an invalid address instead of rejecting the malformed value. DHCP must be enabled; it is disabled by default on APOGEE, Desigo, and TALON devices, while successful exploitation disrupts network service and alters addressing.

The record

CVE
CVE-2019-13939
Published
Jan 16, 2020
Updated
Jun 10, 2025
Vendor
Siemens
Product
TALON TC Compact (BACnet)
Classifications
CWE-20, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 16, 2020CVE publishedPublication date reported by the CVE source.
  2. Jun 10, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <V3.5.3

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Siemens · TALON TC Compact (BACnet)version=0 <V3.5.3
Siemens · Capital Embedded AR Classicversion=0 <*; version=0 <V2303
Siemens · APOGEE PXC Modular (P2 Ethernet)version=V2.8.2 <V2.8.19
Siemens · Desigo PXC00-Uversion=All versions >= V2.3x and < V6.00.327
Siemens · Desigo PXC100-E.Dversion=V2.3 <V6.0.327
Siemens · Desigo PXC22-E.Dversion=V2.3 <V6.0.327
Siemens · Desigo PXM20-Eversion=V2.3 <V6.0.327
Siemens · Nucleus Source Codeversion=0 <*
Siemens · Desigo PXC22.1-E.Dversion=V2.3 <V6.0.327
Siemens · SIMOTICS CONNECT 400version=All versions < V0.3.0.330
Siemens · Nucleus NET for Nucleus PLUSversion=0 <*
Siemens · Nucleus ReadyStart V3version=0 <V2017.02.3
Siemens · APOGEE PXC Compact (BACnet)version=0 <V3.5.3
Siemens · TALON TC Modular (BACnet)version=0 <V3.5.3
Siemens · Desigo PXC64-Uversion=All versions >= V2.3x and < V6.00.327
Siemens · Desigo PXC50-E.Dversion=V2.3 <V6.0.327
Siemens · Desigo PXC12-E.Dversion=V2.3 <V6.0.327
Siemens · Desigo PXC36.1-E.Dversion=V2.3 <V6.0.327
Siemens · APOGEE PXC Modular (BACnet)version=0 <V3.5.3
Siemens · APOGEE PXC Compact (P2 Ethernet)version=V2.8.2 <V2.8.19
Siemens · Desigo PXC00-E.Dversion=V2.3 <V6.0.327
Siemens · Desigo PXC001-E.Dversion=V2.3 <V6.0.327
Siemens · Desigo PXC128-Uversion=All versions >= V2.3x and < V6.00.327
Siemens · Desigo PXC200-E.Dversion=V2.3 <V6.0.327

Published CVSS scores

7.1Siemens ProductCERTCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
7.1Siemens ProductCERTCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
4.8NIST NVDAV:A/AC:L/Au:N/C:N/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo