CVE-2021-31893: Siemens SIMATIC Pcs Firmware

High severity, CVSS 7.8. EPSS: 0.6% chance of exploitation in the next 30 days.

A vulnerability has been identified in SIMATIC PCS 7 V8.2 and earlier (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3), SIMATIC PDM (All versions < V9.2), SIMATIC STEP 7 V5.X (All versions < V5.6 SP2 HF3), SINAMICS STARTER (containing STEP 7 OEM version) (All versions < V5.4 HF2). The affected software contains a buffer overflow vulnerability while handling certain files that could allow a local attacker to trigger a denial-of-service condition or potentially lead to remote code execution.

Affected products

• Siemens SIMATIC Pcs Firmware: up to and including 8.2; version 9.0 only
• Siemens SIMATIC Pdm Firmware: before 9.2 (fixed in 9.2)
• Siemens SIMATIC Step 7 Firmware: up to and including 5.6
• Siemens Sinamics Starter Firmware: before 5.4 (fixed in 5.4); version 5.4 only

Published 2021-07-13. Last modified 2026-06-17.