Vulnerability Database

328,409

Total vulnerabilities in the database

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.

  • Published: Feb 9, 2022
  • Updated: Nov 16, 2025
  • CVE: CVE-2021-37185
  • Severity: High
  • Exploit:

CVSS v3:

  • Severity: High
  • Score: 7.5
  • AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v2:

  • Severity: High
  • Score: 7.1
  • AV:N/AC:M/Au:N/C:N/I:N/A:C

CWEs:

Software From Fixed in
siemens / simatic_drive_controller_cpu_1504d_tf_firmware - 2.9.4
siemens / simatic_drive_controller_cpu_1507d_tf_firmware - 2.9.4
siemens / simatic_et_200sp_open_controller_cpu_1515sp_pc2_firmware - -
siemens / simatic_s7-plcsim_advanced_firmware - 4.0
siemens / simatic_s7-plcsim_advanced_firmware 4.0 4.0.x
siemens / tim_1531_irc_firmware 2.2 2.2.x
siemens / simatic_s7-1500_software_controller - -
siemens / simatic_s7-1200_cpu_1211c_firmware 4.5.0 4.5.2
siemens / simatic_s7-1200_cpu_1212c_firmware 4.5.0 4.5.2
siemens / simatic_s7-1200_cpu_1212fc_firmware 4.5.0 4.5.2
siemens / simatic_s7-1200_cpu_1214fc_firmware 4.5.0 4.5.2
siemens / simatic_s7-1200_cpu_1214c_firmware 4.5.0 4.5.2
siemens / simatic_s7-1200_cpu_1215fc_firmware 4.5.0 4.5.2
siemens / simatic_s7-1200_cpu_1215c_firmware 4.5.0 4.5.2
siemens / simatic_s7-1200_cpu_1217c_firmware 4.5.0 4.5.2
siemens / simatic_s7-1500_cpu_1510sp-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1510sp_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1511-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1511c-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1511f-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1511t-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1511tf-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1512c-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1512sp-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1512spf-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1513-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1513f-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1513r-1_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_cpu_1513prof-2_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_cpu_1513pro-2_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1515-2_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1515f-2_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1515r-2_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1515t-2_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1515tf-2_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1516pro_f_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1516pro-2_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1516-3_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1516f-3_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1516t-3_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1516tf-3_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1517-3_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1517f-3_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1517tf-3_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1518-4_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1518f-4_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1518hf-4_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1518t-4_firmware 2.9.2 2.9.4
siemens / simatic_s7-1500_cpu_1518tf-4_firmware 2.9.2 2.9.4

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.