Improper input validation in Siemens SIMATIC S7-400 CPU hardware version 4.0 and below…
Priority LOW 37CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA.
Summary
A vulnerability has been identified in SIMATIC S7-400 (incl. F) CPU hardware version 4.0 and below (All versions), SIMATIC S7-400 (incl. F) CPU hardware version 5.0 (All firmware versions < V5.2), SIMATIC S7-400H CPU hardware version 4.5 and below (All versions). The affected CPUs improperly validate S7 communication packets which could cause a Denial-of-Service condition of the CPU. The CPU will remain in DEFECT mode until manual restart.
Why it matters now
EPSS 0.02377 83rd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Siemens | SIMATIC S7-400 (incl. F) CPU hardware version 4.0 and below, SIMATIC S7-400 (incl. F) CPU hardware version 5.0, SIMATIC S7-400H CPU hardware version 4.5 and below | SIMATIC S7-400 (incl. F) CPU hardware version 4.0 and below : All versions; SIMATIC S7-400 (incl. F) CPU hardware version 5.0 : All firmware versions < V5.2; SIMATIC S7-400H CPU hardware version 4.5 and below : All versions | — | No fix listed | CNA |
- SIMATIC S7-400 (incl. F) CPU hardware version 4.0 and below, SIMATIC S7-400 (incl. F) CPU hardware version 5.0, SIMATIC S7-400H CPU hardware version 4.5 and below VendorSiemens Affected SIMATIC S7-400 (incl. F) CPU hardware version 4.0 and below : All versions; SIMATIC S7-400 (incl. F) CPU hardware version 5.0 : All firmware versions < V5.2; SIMATIC S7-400H CPU hardware version 4.5 and below : All versions Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:siemens:simatic_s7-400_firmware:*:*:*:*:*:*:*:* | up to 4.0 | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_s7-400:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_s7-400_firmware:*:*:*:*:*:*:*:* | before 5.2 | Vulnerable | Siemens |
| cpe:2.3:o:siemens:simatic_s7-400h_firmware:*:*:*:*:*:*:*:* | up to 4.5 | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_s7-400h:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
- cpe:2.3:o:siemens:simatic_s7-400_firmware:*:*:*:*:*:*:*:* Versions up to 4.0 Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_s7-400:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_s7-400_firmware:*:*:*:*:*:*:*:* Versions before 5.2 Vulnerable ·Siemens
- cpe:2.3:o:siemens:simatic_s7-400h_firmware:*:*:*:*:*:*:*:* Versions up to 4.5 Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_s7-400h:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2018-4850
- 2026-10-03 Alias added: GHSA-9c5r-829c-7rjc
References
More Siemens Simatic S7-400 Firmware vulnerabilities
- TI-2018-11877 Improper signature verification in Siemens SIMATIC S7-400 CPU 412-1 DP V7 CVSS 3.1HIGH 8.2
- TI-2018-11876 Improper input validation in Siemens SIMATIC S7-400 CPU 412-1 DP V7 CVSS 3.1HIGH 7.5
- TI-2017-01922 Uncontrolled resource consumption in Siemens Development/Evaluation Kits for PROFINET IO… CVSS 4.0HIGH 7.1
- TI-2017-01923 Uncontrolled resource consumption in Siemens Development/Evaluation Kits for PROFINET IO… CVSS 4.0HIGH 7.1
Sources
- CVE-2018-4850 · CVE Program
- CVE-2018-4850 · NVD
- FIRST EPSS
- GHSA-9c5r-829c-7rjc · GitHub Advisory Database · CC BY 4.0
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