CVE-2021-33716: Siemens SIMATIC CP 1543-1 Firmware

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

A vulnerability has been identified in SIMATIC CP 1543-1 (incl. SIPLUS variants) (All versions < V3.0), SIMATIC CP 1545-1 (All versions < V1.1). An attacker with access to the subnet of the affected device could retrieve sensitive information stored in cleartext.

Affected products

• Siemens SIMATIC CP 1543-1 Firmware: before 3.0 (fixed in 3.0)
• Siemens SIMATIC CP 1545-1 Firmware: before 1.1 (fixed in 1.1)

Published 2021-09-14. Last modified 2026-06-17.