Vulnerability in Siemens Sidoor Atd430w
CVE-2025-40820
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (41.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Siemens Sidoor Atd430w — versions 0
- Siemens Sidoor Ate530g Coated — versions 0
- Siemens Sidoor Ate530s Coated — versions 0
- Siemens Simatic Cfu Diq — versions 0
- Siemens Simatic Cfu Pa — versions 0
- Siemens Simatic Et 200al Im 157-1 Pn — versions 0
- Siemens Simatic Et 200clean, Cm 8x Io-Link — versions 0
- Siemens Simatic Et 200clean, Di 16x24vdc — versions 0
- Siemens Simatic Et 200clean, Diq 16x24vdc/0,5a — versions 0
- Siemens Simatic Et 200eco Pn, Ai 8xrtd/tc, M12-L — versions V5.1.1
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2025-40820?
- CVE-2025-40820 is a high-severity vulnerability in Siemens Sidoor Atd430w, classified under Improper Verification of Source of a Communication Channel. CVSS score: 7.5/10. Published 2025-12-09.
- How severe is CVE-2025-40820?
- High severity. CVSS v3 base score is 7.5 out of 10.