Auth bypass in Siemens Simatic Cp 1542sp-1

CVE-2025-40771

A vulnerability has been identified in SIMATIC CP 1542SP-1 (6GK7542-6UX00-0XE0) (All versions < V2.4.24), SIMATIC CP 1542SP-1 IRC (6GK7542-6VX00-0XE0) (All versions < V2.4.24), SIMATIC CP 1543SP-1 (6GK7543-6WX00-0XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1542SP-1 IRC TX RAIL (6AG2542-6VX00-4XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1543SP-1 ISEC (6AG1543-6WX00-7XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1543SP-1 ISEC TX RAIL (6AG2543-6WX00-4XE0) (All versions < V2.4.24). Affected devices do not properly authenticate configuration connections. This could allow an unauthenticated remote attacker to access the configuration data.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (42.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-40771: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-40771?
CVE-2025-40771 is a critical-severity vulnerability in Siemens Simatic Cp 1542sp-1, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2025-10-14.
How severe is CVE-2025-40771?
Critical severity. CVSS v3 base score is 9.8 out of 10.