CVE-2025-40944
Siemens · published 2026-01-13
Source record Collected from the National Vulnerability Database (NVD)
Description
Description by Siemens AG via the CVE Program.
A vulnerability has been identified in SIMATIC ET 200AL IM 157-1 PN (6ES7157-1AB00-0AB0) (All versions), SIMATIC ET 200MP IM 155-5 PN HF (6ES7155-5AA00-0AC0) (All versions >= V4.2.0), SIMATIC ET 200SP IM 155-6 MF HF (6ES7155-6MU00-0CN0) (All versions), SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) (All versions < V1.3), SIMATIC ET 200SP IM 155-6 PN R1 (6ES7155-6AU00-0HM0) (All versions < V6.0.1), SIMATIC ET 200SP IM 155-6 PN/2 HF (6ES7155-6AU01-0CN0) (All versions >= V4.2.0 < V4.2.5), SIMATIC ET 200SP IM 155-6 PN/3 HF (6ES7155-6AU30-0CN0) (All versions < V4.2.2), SIMATIC PN/MF Coupler (6ES7158-3MU10-0XA0) (All versions), SIMATIC PN/PN Coupler (6ES7158-3AD10-0XA0) (All versions < V6.0.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-2AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-7AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL (6AG2155-5AA00-1AC0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-2CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-7CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL (6AG2155-6AU01-1CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS ET 200SP IM 155-6 PN HF TX RAIL (6AG2155-6AU01-4CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS NET PN/PN Coupler (6AG2158-3AD10-4XA0) (All versions < V6.0.0). Affected devices do not properly handle S7 protocol session disconnect requests. When receiving a valid S7 protocol Disconnect Request (COTP DR TPDU) on TCP port 102, the devices enter an improper session state. This could allow an attacker to cause the device to become unresponsive, leading to a denial-of-service condition that requires a power cycle to restore normal operation.
Status at the source
- NVD status: Deferred — NVD has not analysed this CVE.
Affected products, as the source lists them
| Vendor | Product | Versions |
|---|---|---|
| Siemens | SIMATIC ET 200AL IM 157-1 PN | 0 – before *: affected |
| Siemens | SIMATIC ET 200MP IM 155-5 PN HF | V4.2.0 – before *: affected |
| Siemens | SIMATIC ET 200SP IM 155-6 MF HF | 0 – before *: affected |
| Siemens | SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) | 0 – before V1.3: affected |
| Siemens | SIMATIC ET 200SP IM 155-6 PN R1 | 0 – before V6.0.1: affected |
| Siemens | SIMATIC ET 200SP IM 155-6 PN/2 HF | V4.2.0 – before V4.2.5: affected |
| Siemens | SIMATIC ET 200SP IM 155-6 PN/3 HF | 0 – before V4.2.2: affected |
| Siemens | SIMATIC PN/MF Coupler | 0 – before *: affected |
| Siemens | SIMATIC PN/PN Coupler | 0 – before V6.0.0: affected |
| Siemens | SIPLUS ET 200MP IM 155-5 PN HF | V4.2.0 – before *: affected |
| Siemens | SIPLUS ET 200MP IM 155-5 PN HF | V4.2.0 – before *: affected |
| Siemens | SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL | V4.2.0 – before *: affected |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF | V4.2.0 – before V4.2.5: affected |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF | V4.2.0 – before V4.2.5: affected |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL | V4.2.0 – before V4.2.5: affected |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF TX RAIL | V4.2.0 – before V4.2.5: affected |
| Siemens | SIPLUS NET PN/PN Coupler | 0 – before V6.0.0: affected |
DeSpy has not checked any unit, hardware revision or firmware. A product missing here is not a statement that it is unaffected.
Scores, as their sources published them
- CVSS 4.0: 8.7 HIGH — as published by Siemens AG (Secondary)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1: 7.5 HIGH — as published by Siemens AG (Secondary)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - SSVC — CISA's assessment (SSVC 2.0.3, CISA Coordinator): Exploitation: none · Automatable: yes · Technical impact: partial
DeSpy does not score records. These are the sources' own values.
Weaknesses
Sources
References the source lists
Source dates: published 2026-01-13, last changed 2026-06-17. DeSpy's copy of this version is dated 2026-09-28.
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