PT-2025-49844 · Siemens · Simatic Cn 4100

Published 2025-12-09 · Updated 2025-12-09 · CVE-2025-40939

Positive Technologies (AI Summary)

CVSS v2.0

4.9

Medium

Base vector

AV:L/AC:L/Au:N/C:N/I:N/A:C

Name of the Vulnerable Software and Affected Versions SIMATIC CN 4100 versions prior to 4.0.1

Description The SIMATIC CN 4100 device contains a USB port that allows unauthenticated connections. An attacker with physical access can exploit this to trigger a reboot, potentially causing a denial of service condition.

Recommendations Update to version 4.0.1 or later.

Fix

Improper Access Control

Weakness Enumeration

CWE-284

Related Identifiers

BDU:2026-00142

CVE-2025-40939

Affected Products

Simatic Cn 4100

References · 5

• https://cert-portal.siemens.com/productcert/html/ssa-416652.html · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-40939 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-40939 · Security Note
• https://bdu.fstec.ru/vul/2026-00142 · Security Note
• https://twitter.com/CVEnew/status/1998355316245991716 · Twitter Post