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Fencer Vulns
high 7.5

CVE-2021-37204 json

A vulnerability has been identified in SIMATIC Drive Controller family (All versions < V2.9.2), SIMATIC Drive Controller family (All versio…

published 2022-02-09 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-23778

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.2%
EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

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.

Patch / fix

  • 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-plcsim_advanced_firmware 4.0
  • 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_1214fc_firmware 4.5.2
  • siemens simatic_s7-1200_cpu_1214c_firmware 4.5.2
  • siemens simatic_s7-1200_cpu_1215fc_firmware 4.5.2
  • siemens simatic_s7-1200_cpu_1215c_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
  • siemens simatic_s7-1500_cpu_1511-1_firmware 2.9.4
  • siemens simatic_s7-1500_cpu_1511c-1_firmware 2.9.4
  • siemens simatic_s7-1500_cpu_1511f-1_firmware 2.9.4
  • siemens simatic_s7-1500_cpu_1511t-1_firmware 2.9.4
  • siemens simatic_s7-1500_cpu_1511tf-1_firmware 2.9.4
  • siemens simatic_s7-1500_cpu_1512c-1_firmware 2.9.4
  • siemens simatic_s7-1500_cpu_1512sp-1_firmware 2.9.4

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-22-041-01 updated cvss 7.5

Siemens SIMATIC Industrial Products (Update A)

  • Siemens SIMATIC Drive Controller family <V2.9.2, >=V2.9.2<V2.9.4
    affected: fixed in V2.9.4 support.industry.siemens.com
  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC (incl. SIPLUS variants)
    affected: no fix planned
  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) <V21.9, >=V21.9<V21.9.4
    affected: fixed in V21.9.4 support.industry.siemens.com
  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC2 Ready4Linux
    affected: no fix planned
  • Siemens SIMATIC S7-1200 CPU family (incl. SIPLUS variants) <V4.5.0, >=V4.5.0<V4.5.2
    affected: fixed in V4.5.2 support.industry.siemens.com
  • Siemens SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants) <V2.9.2, >=V2.9.2<V2.9.4
    affected: fixed in V2.9.4 support.industry.siemens.com
  • Siemens SIMATIC S7-1500 Software Controller <V21.9, >=V21.9<V21.9.4
    affected: fixed in V21.9.4 support.industry.siemens.com
  • Siemens SIMATIC S7-PLCSIM Advanced <V4.0, >=V4.0, <V4.0_SP1
    affected: fixed in V4.0 support.industry.siemens.com
show 1 more
  • Siemens SIPLUS TIM 1531 IRC (6AG1543-1MX00-7XE0) <V2.3.6 Siemens TIM 1531 IRC (6GK7543-1MX00-0XE0) <V2.3.6
    affected: fixed in V2.3.6 support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
18 mo ago

Exploit prediction

2.18% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 7.1 AV:N/AC:M/Au:N/C:N/I:N/A:C

Affected products

  • Siemens SIMATIC Drive Controller family
  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC (incl. SIPLUS variants)
  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants)
  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC2 Ready4Linux
  • Siemens SIMATIC S7-1200 CPU family (incl. SIPLUS variants)
  • Siemens SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants)
  • Siemens SIMATIC S7-1500 Software Controller
  • Siemens SIMATIC S7-PLCSIM Advanced
  • Siemens SIPLUS TIM 1531 IRC
  • Siemens TIM 1531 IRC

Classification

Weakness
  • CWE-672 Operation on a Resource after Expiration or Release

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.