CVE-2025-40820
7.5CVSSHIGH
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.
CVSS Vector Breakdown
Exploitability
AV:NAttack VectorNetwork
AC:LAttack ComplexityLow
PR:NPrivileges RequiredNone
UI:NUser InteractionNone
Scope
S:UScopeUnchanged
Impact
C:NConfidentialityNone
I:NIntegrityNone
A:HAvailabilityHigh
Weaknesses
Affected Products
and 170 more affected products View all →
Exploitability
Official Patch Available
Workaround Available
References
https://cert-portal.siemens.com/productcert/html/ssa-915282.html
cert-portal.siemens.com
https://cert-portal.siemens.com/productcert/csaf/ssa-915282.json
cert-portal.siemens.com
https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2025/icsa-25-352-05.json
raw.githubusercontent.com
and 7 more references View all →
Timeline
Published
Dec 9, 2025
Last Updated
Dec 9, 2025
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