Siemens APOGEE PXC and TALON TC Series Expected Behavior Violation (CVE-2025-40555)

medium Tenable OT Security Plugin ID 504803

Synopsis

The remote OT asset is affected by a vulnerability.

Description

Affected devices start sending unsolicited BACnet broadcast messages after processing a specific BACnet createObject request. This could allow an attacker residing in the same BACnet network to send a specially crafted message that results in a partial denial of service condition of the targeted device, and potentially reduce the availability of BACnet network. A power cycle is required to restore the device's normal operation.

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Solution

The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at CISA.gov.

Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:

- APOGEE PXC+TALON TC Series (BACnet): Currently no fix is planned

As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following recommendations in the product manuals.

Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage

For more information see the associated Siemens security advisory SSA-718393 in HTML and CSAF.

Plugin Details

Severity: Medium

ID: 504803

File Name: tenable_ot_siemens_CVE-2025-40555.nasl

Version: 1.3

Type: remote

Family: Tenable.ot

Published: 11/18/2025

Updated: 3/12/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 1.6

CVSS v2

Risk Factor: Low

Base Score: 3.3

Temporal Score: 2.4

Vector: CVSS2#AV:A/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2025-40555

CVSS v3

Risk Factor: Medium

Base Score: 4.7

Temporal Score: 4.1

Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:siemens:apogee_pxc_modular_firmware, cpe:/o:siemens:apogee_pxc_compact_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 5/13/2025

Vulnerability Publication Date: 5/13/2025

Reference Information

CVE: CVE-2025-40555

CWE: 440

Detections

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