Improper input validation in Siemens Simatic S7-1200 CPU V1 Family (Incl. Siplus Variants)

CVE-2011-20001

A vulnerability has been identified in SIMATIC S7-1200 CPU V1 family (incl. SIPLUS variants) (All versions < V2.0.3), SIMATIC S7-1200 CPU V2 family (incl. SIPLUS variants) (All versions < V2.0.3). The web server interface of affected devices improperly processes incoming malformed HTTP traffic at high rate. This could allow an unauthenticated remote attacker to force the device entering the stop/defect state, thus creating a denial of service condition.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

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 (38.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2011-20001: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2011-20001?
CVE-2011-20001 is a high-severity vulnerability in Siemens Simatic S7-1200 CPU V1 Family (Incl. Siplus Variants), classified under Improper Input Validation. CVSS score: 7.5/10. Published 2025-10-14.
How severe is CVE-2011-20001?
High severity. CVSS v3 base score is 7.5 out of 10.