CVE-2025-40944
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), 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), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-7CN0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL (6AG2155-6AU01-1CN0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF TX RAIL (6AG2155-6AU01-4CN0) (All versions >= V4.2.0), 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.
EPSS 0.40% · 32.6th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Siemens | SIMATIC ET 200SP IM 155-6 PN R1 | 0, 0 |
| Siemens | SIMATIC ET 200SP IM 155-6 PN/2 HF | V4.2.0, V4.2.0 |
| Siemens | SIMATIC | |
| Siemens | SIPLUS NET PN/PN Coupler | 0, 0 |
| Siemens | SIMATIC PN/PN Coupler | 0, 0 |
| Siemens | SIMATIC ET 200AL IM 157-1 PN | 0, 0 |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF | V4.2.0, V4.2.0, V4.2.0 |
| Siemens | SIPLUS ET 200MP IM 155-5 PN HF | V4.2.0, V4.2.0, V4.2.0 |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL | V4.2.0, V4.2.0 |
| Siemens | SIMATIC ET 200MP IM 155-5 PN HF | V4.2.0, V4.2.0 |
| Siemens | N/A | |
| Siemens | SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL | V4.2.0, V4.2.0 |
| Siemens | SIMATIC ET 200SP IM 155-6 MF HF | 0, 0 |
| Siemens | SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) | 0, 0 |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF TX RAIL | V4.2.0, V4.2.0 |
| Siemens | SIMATIC ET 200SP IM 155-6 PN/3 HF | 0, 0 |
| Siemens | SCALANCE | |
| Siemens | SIMATIC PN/MF Coupler | 0, 0 |
Timeline
- Jan 13, 2026 EPSS Score
- Jan 13, 2026 CVE Published
- Jan 13, 2026 PoC Published
- Jan 13, 2026 PoC Published
- Jan 13, 2026 PoC Published
- Jan 16, 2026 EPSS Score
- Jan 19, 2026 EPSS Score
- Jan 22, 2026 EPSS Score
- Jan 25, 2026 EPSS Score
- Jan 28, 2026 EPSS Score
- Jan 31, 2026 EPSS Score
- Feb 3, 2026 EPSS Score
References
- https://cert-portal.siemens.com/productcert/html/ssa-674753.html url
- https://cert-portal.siemens.com/productcert/html/ssb-491780.html advisory
- https://nvd.nist.gov/vuln/detail/CVE-2025-40944 advisory
- https://cert-portal.siemens.com/productcert/html/ssa-001536.html advisory
- https://cert-portal.siemens.com/productcert/html/ssa-507364.html advisory