SecuriTricks - CVE-2025-40820

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.

Product(s) Impacted

Vendor	Product	Versions
Siemens	Tcp Service	*

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-940

Improper Verification of Source of a Communication Channel

The product establishes a communication channel to handle an incoming request that has been initiated by an actor, but it does not properly verify that the request is coming from the expected origin.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	siemens	tcp_service	/	/	/	/	/	/	/	/

References

https://cert-portal.siemens.com/productcert/html/ssa-915282.html

CVSS Score

8.7 / 10

CVSS Data - 4.0

Attack Vector: NETWORK
Attack Complexity: LOW
Attack Requirements: NONE
Privileges Required: NONE
User Interaction: NONE
Scope:
Confidentiality Impact: NONE
Integrity Impact: NONE
Availability Impact: HIGH
Exploit Maturity: NOT_DEFINED

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

View Vector String

Timeline

Published: Dec. 9, 2025, 4:17 p.m.
Last Modified: Dec. 9, 2025, 6:36 p.m.

Status : Awaiting Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

productcert@siemens.com

CVE-2025-40820