CVE-2021-37204

Severity: high (CVSS 7.1 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-02-09 · updated 2026-06-17
Weakness: CWE-672

Description

A vulnerability has been identified in SIMATIC Drive Controller family (All versions < V2.9.2), SIMATIC Drive Controller family (All versions >= V2.9.2 < V2.9.4), SIMATIC ET 200SP Open Controller CPU 1515SP PC (incl. SIPLUS variants) (All versions), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions < V21.9), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions >= V21.9 < V21.9.4), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 Ready4Linux (All versions), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (All versions < V4.5.0), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (All versions >= V4.5.0 < V4.5.2), SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions < V2.9.2), SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions >= V2.9.2 < V2.9.4), SIMATIC S7-1500 Software Controller (All versions < V21.9), SIMATIC S7-1500 Software Controller (All versions >= V21.9 < V21.9.4), SIMATIC S7-PLCSIM Advanced (All versions < V4.0), SIMATIC S7-PLCSIM Advanced (All versions >= V4.0 < V4.0 SP1), SIPLUS TIM 1531 IRC (All versions < V2.3.6), TIM 1531 IRC (All versions < V2.3.6). An unauthenticated attacker could cause a denial-of-service condition in a PLC when sending specially prepared packet over port 102/tcp. A restart of the affected device is needed to restore normal operations.

Affected products

Siemens Simatic Drive Controller Cpu 1504D Tf Firmware: before 2.9.4 — fixed in 2.9.4
Siemens Simatic Drive Controller Cpu 1507D Tf Firmware: before 2.9.4 — fixed in 2.9.4
Siemens Simatic Et 200Sp Open Controller Cpu 1515Sp Pc2 Firmware: all versions
Siemens Simatic S7-1200 Cpu 1211C Firmware: from 4.5.0 before 4.5.2 — fixed in 4.5.2
Siemens Simatic S7-1200 Cpu 1212C Firmware: from 4.5.0 before 4.5.2 — fixed in 4.5.2
Siemens Simatic S7-1200 Cpu 1212Fc Firmware: from 4.5.0 before 4.5.2 — fixed in 4.5.2
Siemens Simatic S7-1200 Cpu 1214C Firmware: from 4.5.0 before 4.5.2 — fixed in 4.5.2
Siemens Simatic S7-1200 Cpu 1214Fc Firmware: from 4.5.0 before 4.5.2 — fixed in 4.5.2
Siemens Simatic S7-1200 Cpu 1215C Firmware: from 4.5.0 before 4.5.2 — fixed in 4.5.2
Siemens Simatic S7-1200 Cpu 1215Fc Firmware: from 4.5.0 before 4.5.2 — fixed in 4.5.2
Siemens Simatic S7-1200 Cpu 1217C Firmware: from 4.5.0 before 4.5.2 — fixed in 4.5.2
Siemens Simatic S7-1500 Cpu 1510Sp-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1510Sp Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1511-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1511C-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1511F-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1511T-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1511Tf-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1512C-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1512Sp-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1512Spf-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1513-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1513F-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1513R-1 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1515-2 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1515F-2 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1515R-2 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1515T-2 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1515Tf-2 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4
Siemens Simatic S7-1500 Cpu 1516-3 Firmware: from 2.9.2 before 2.9.4 — fixed in 2.9.4

How to fix

Upgrade to a fixed version: Siemens Simatic Drive Controller Cpu 1504D Tf Firmware 2.9.4; Siemens Simatic Drive Controller Cpu 1507D Tf Firmware 2.9.4; Siemens Simatic S7-1200 Cpu 1211C Firmware 4.5.2; Siemens Simatic S7-1200 Cpu 1212C Firmware 4.5.2; Siemens Simatic S7-1200 Cpu 1212Fc Firmware 4.5.2; Siemens Simatic S7-1200 Cpu 1214C Firmware 4.5.2; Siemens Simatic S7-1200 Cpu 1214Fc Firmware 4.5.2; Siemens Simatic S7-1200 Cpu 1215C Firmware 4.5.2; Siemens Simatic S7-1200 Cpu 1215Fc Firmware 4.5.2; Siemens Simatic S7-1200 Cpu 1217C Firmware 4.5.2; Siemens Simatic S7-1500 Cpu 1510Sp-1 Firmware 2.9.4; Siemens Simatic S7-1500 Cpu 1510Sp Firmware 2.9.4. Check the vendor advisory for mitigations.

References

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