CVE-2011-20001: Siemens SIMATIC s7-1200 CPU v1 Family Incl. Siplus Variants

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Siemens SIMATIC s7-1200 CPU v1 Family Incl. Siplus Variants: before V2.0.3 (fixed in V2.0.3)
• Siemens SIMATIC s7-1200 CPU v2 Family Incl. Siplus Variants: before V2.0.3 (fixed in V2.0.3)

Published 2025-10-14. Last modified 2026-06-16.