How severe is CVE-2021-37185?

CVE-2021-37185 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-37185 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-37185?

CVE-2021-37185 primarily affects Siemens Simatic Drive Controller Cpu 1504d Tf Firmware. In total, 49 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-37185?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-37185 published?

CVE-2021-37185 was published on 2022-02-09 and last updated on 2026-06-17.

CVE-2021-37185

CVE-2021-37185 is a high-severity vulnerability in Siemens Simatic Drive Controller Cpu 1504d Tf Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-672.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.1
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-672
Affected product: Siemens Simatic Drive Controller Cpu 1504d Tf Firmware
Published: 2022-02-09
Last modified: 2026-06-17

Description

A vulnerability has been identified in SIMATIC Drive Controller family (All versions >= V2.9.2 < V2.9.4), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions >= V21.9 < V21.9.4), 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 < V2.9.4), SIMATIC S7-1500 Software Controller (All versions >= V21.9 < V21.9.4), 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 packets over port 102/tcp. A restart of the affected device is needed to restore normal operations.

Frequently asked questions

What is CVE-2021-37185?: A vulnerability has been identified in SIMATIC Drive Controller family (All versions >= V2.9.2 < V2.9.4), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions >= V21.9 < V21.9.4), 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 < V2.9.4), SIMATIC S7-1500 Software Controller (All versions >= V21.9 < V21.9.4), 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 packets over port 102/tcp. A restart of the affected device is needed to restore normal operations.
How severe is CVE-2021-37185?: CVE-2021-37185 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-37185 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37185?: CVE-2021-37185 primarily affects Siemens Simatic Drive Controller Cpu 1504d Tf Firmware. In total, 49 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-37185?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-37185 published?: CVE-2021-37185 was published on 2022-02-09 and last updated on 2026-06-17.

References

https://cert-portal.siemens.com/productcert/pdf/ssa-838121.pdf

Affected products (49)

cpe:2.3:o:siemens:simatic_drive_controller_cpu_1504d_tf_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_drive_controller_cpu_1507d_tf_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_et_200sp_open_controller_cpu_1515sp_pc2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-plcsim_advanced_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-plcsim_advanced_firmware:4.0:-:*:*:*:*:*:*
cpe:2.3:o:siemens:tim_1531_irc_firmware:*:*:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_s7-1500_software_controller:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1200_cpu_1211c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1200_cpu_1212c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1200_cpu_1212fc_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1200_cpu_1214fc_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1200_cpu_1214c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1200_cpu_1215fc_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1200_cpu_1215c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1200_cpu_1217c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1510sp-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1510sp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511c-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511f-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511t-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511tf-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1512c-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1512sp-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1512spf-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1513-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1513f-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1513r-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_cpu_1513prof-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_cpu_1513pro-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515f-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515r-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515t-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515tf-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516pro_f_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516pro-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516-3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516f-3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516t-3_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Siemens Simatic Drive Controller Cpu 1504d Tf Firmware

CVE-2022-38465 — Critical (CVSS 9.3): A vulnerability has been identified in SIMATIC Drive Controller family (All versions < V2.9.2), SIMATIC ET 200SP Open…
CVE-2023-46156 — High (CVSS 7.5): Affected devices improperly handle specially crafted packets sent to port 102/tcp. This could allow an attacker to…
CVE-2023-28831 — High (CVSS 7.5): The OPC UA implementations (ANSI C and C++) in affected products contain an integer overflow vulnerability that could…
CVE-2021-37205 — High (CVSS 7.5): A vulnerability has been identified in SIMATIC Drive Controller family (All versions >= V2.9.2 < V2.9.4), SIMATIC ET…
CVE-2021-37204 — High (CVSS 7.5): A vulnerability has been identified in SIMATIC Drive Controller family (All versions < V2.9.2), SIMATIC Drive…
CVE-2022-30694 — Medium (CVSS 6.5): The login endpoint /FormLogin in affected web services does not apply proper origin checking. This could allow…

All CVEs affecting Siemens Simatic Drive Controller Cpu 1504d Tf Firmware →

Other CWE-672 (Operation on a Resource after Expiration or Release) vulnerabilities

CVE-2023-41094 — Critical (CVSS 10.0): TouchLink packets processed after timeout or out of range due to Operation on a Resource after Expiration and Missing…
CVE-2020-24030 — Critical (CVSS 9.8): ForLogic Qualiex v1 and v3 has weak token expiration. This allows remote unauthenticated privilege escalation and…
CVE-2020-12043 — Critical (CVSS 9.8): The Baxter Spectrum WBM (v17, v20D29, v20D30, v20D31, and v22D24) when configured for wireless networking the FTP…
CVE-2019-17638 — Critical (CVSS 9.4): In Eclipse Jetty, versions 9.4.27.v20200227 to 9.4.29.v20200521, in case of too large response headers, Jetty throws an…
CVE-2013-10075 — Critical (CVSS 9.1): Apache::Session versions through 1.94 for Perl re-creates deleted sessions. The session stores…
CVE-2022-22755 — High (CVSS 8.8): By using XSL Transforms, a malicious webserver could have served a user an XSL document that would continue to execute…

Browse all CWE-672 (Operation on a Resource after Expiration or Release) vulnerabilities →