CVE-2021-37206: Siemens Siprotec 5 With CPU Variant CP050

High severity, CVSS 7.5. EPSS: 1.4% chance of exploitation in the next 30 days.

A vulnerability has been identified in SIPROTEC 5 relays with CPU variants CP050 (All versions < V8.80), SIPROTEC 5 relays with CPU variants CP100 (All versions < V8.80), SIPROTEC 5 relays with CPU variants CP300 (All versions < V8.80). Received webpackets are not properly processed. An unauthenticated remote attacker with access to any of the Ethernet interfaces could send specially crafted packets to force a restart of the target device.

Affected products

• Siemens Siprotec 5 With CPU Variant CP050: before 8.80 (fixed in 8.80)
• Siemens Siprotec 5 With CPU Variant CP100: before 8.80 (fixed in 8.80)
• Siemens Siprotec 5 With CPU Variant CP300: before 8.80 (fixed in 8.80)

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