CVE-2021-33716

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-09-14 · updated 2026-06-17
Weakness: CWE-312

Description

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 V4.0: before 3.0 — fixed in 3.0
Siemens Simatic Cp 1545-1 Firmware: before 1.1 — fixed in 1.1

How to fix

Upgrade to a fixed version: Siemens SIMATIC CP 1543-1 V4.0 3.0; Siemens Simatic Cp 1545-1 Firmware 1.1. Check the vendor advisory for mitigations.

References

https://cert-portal.siemens.com/productcert/pdf/ssa-535997.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-535997.pdf

Get alerted when CVE-2021-33716 or the next vulnerability affects your stack