Siemens SIMATIC S7-1500 Improper Neutralization of Directives in Dynamically Evaluated Code (CVE-2025-40943)

critical Tenable OT Security Plugin ID 505310

Synopsis

The remote OT asset is affected by a vulnerability.

Description

Affected devices do not properly sanitize contents of trace files.
This could allow an attacker to inject code through social engineering an authorized user, who has the function right Read diagnostics, to import a specially crafted trace file. The malicious trace file is insufficiently sanitized and malicious code could be executed in the clients browser session and trigger PLC operations via the webserver that the legitimate user is authorized to perform.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

Refer to the vendor advisory.

Plugin Details

Severity: Critical

ID: 505310

File Name: tenable_ot_siemens_CVE-2025-40943.nasl

Version: 1.2

Type: remote

Family: Tenable.ot

Published: 3/25/2026

Updated: 3/26/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v3

Risk Factor: Critical

Base Score: 9.6

Temporal Score: 8.3

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

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

CVSS v4

Risk Factor: Critical

Base Score: 9.4

Threat Score: 7.7

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Vulnerability Information

CPE: cpe:/o:siemens:siplus_s7-1500_cpu_firmware, cpe:/o:siemens:simatic_et_200sp_open_controller_cpu_1515sp_pc3_firmware, cpe:/o:siemens:siplus_et_200sp_cpu_firmware, cpe:/o:siemens:simatic_et_200sp_open_controller_cpu_1515sp_pc2_firmware, cpe:/o:siemens:simatic_s7-1500_cpu_firmware, cpe:/o:siemens:simatic_s7-1500_et_200pro_cpu_firmware, cpe:/o:siemens:simatic_et_200sp_open_controller_cpu_1515sp_pc_firmware, cpe:/o:siemens:simatic_s7-1500_cpu_firmware:4.1.2, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:4.1.2, cpe:/o:siemens:simatic_et_200sp_cpu_firmware:4.1.2, cpe:/o:siemens:simatic_drive_controller_cpu_firmware, cpe:/o:siemens:simatic_et_200sp_cpu_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 3/10/2026

Vulnerability Publication Date: 3/10/2026

Reference Information

CVE: CVE-2025-40943

CWE: 95

ICSA: 26-071-04

Detections

Analytics