Affected products do not properly enforce TCP sequence number validation in specific scenarios but accept values within a broad range. This could allow an unauthenticated remote attacker e.g. to interfere with connection setup, potentially leading to a denial of service. The attack succeeds only if an attacker can inject IP packets with spoofed addresses at precisely timed moments, and it affects only TCP-based services.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 10 Dec 2025 18:00:00 +0000

Type Values Removed Values Added
First Time appeared Siemens
Siemens sidoor Atd430w
Siemens sidoor Ate530s Coated
Siemens simatic
Siemens simatic Cfc
Siemens simatic Cfu Diq
Siemens simatic Cfu Pa
Siemens simatic Et200al Im 157-1 Pn
Siemens simatic Et200sp Im155-6 Mf Hf
Siemens simatic Et 200mp Im 155-5 Pn Hf
Siemens simatic Et 200s
Siemens simatic Pcs
Siemens simatic Pdm
Siemens simatic S7-1500 Cpu 1510sp-1 Pn
Siemens simatic S7-1500 Cpu 1510sp F-1 Pn
Siemens simatic S7-1500 Cpu 1512sp-1 Pn
Siemens simatic S7-1500 Cpu 1512sp F-1 Pn
Vendors & Products Siemens
Siemens sidoor Atd430w
Siemens sidoor Ate530s Coated
Siemens simatic
Siemens simatic Cfc
Siemens simatic Cfu Diq
Siemens simatic Cfu Pa
Siemens simatic Et200al Im 157-1 Pn
Siemens simatic Et200sp Im155-6 Mf Hf
Siemens simatic Et 200mp Im 155-5 Pn Hf
Siemens simatic Et 200s
Siemens simatic Pcs
Siemens simatic Pdm
Siemens simatic S7-1500 Cpu 1510sp-1 Pn
Siemens simatic S7-1500 Cpu 1510sp F-1 Pn
Siemens simatic S7-1500 Cpu 1512sp-1 Pn
Siemens simatic S7-1500 Cpu 1512sp F-1 Pn

Tue, 09 Dec 2025 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 09 Dec 2025 11:00:00 +0000

Type Values Removed Values Added
Description Affected products do not properly enforce TCP sequence number validation in specific scenarios but accept values within a broad range. This could allow an unauthenticated remote attacker e.g. to interfere with connection setup, potentially leading to a denial of service. The attack succeeds only if an attacker can inject IP packets with spoofed addresses at precisely timed moments, and it affects only TCP-based services.
Weaknesses CWE-940
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: siemens

Published:

Updated: 2025-12-09T15:55:23.400Z

Reserved: 2025-04-16T08:50:26.975Z

Link: CVE-2025-40820

cve-icon Vulnrichment

Updated: 2025-12-09T15:55:01.982Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-09T16:17:46.413

Modified: 2025-12-09T18:36:53.557

Link: CVE-2025-40820

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-12-10T17:52:04Z

Weaknesses