TCP Sequence Number Validation Flaw in Siemens Products

CVE-2025-40820

What is CVE-2025-40820?

Certain Siemens products exhibit a vulnerability due to inadequate enforcement of TCP sequence number validation in specific scenarios, allowing potential exploitation by unauthenticated remote attackers. This flaw could lead to disruptions in connection setups, creating an opportunity for denial of service. The successful execution of an attack requires the attacker to inject IP packets with spoofed addresses at precisely timed intervals, primarily affecting TCP-based services.

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