CVE-2021-43936

CRITICALNVD 10.09.8▼Elevated

10.0

The software allows the attacker to upload or transfer files of dangerous types to the WebHMI portal, that may be automatically processed within the product's environment or lead to arbitrary code execution.

CVSS v3: 10.0
EG Score: 9.8(medium)
EPSS: 96.6%
KEV: Not listed

Published

December 6, 2021

Last Modified

November 21, 2024

Advisory Details (1)

Auto-updated May 23, 2026

Patch available. Sources: cisa.

cisa Patch Available

Distributed Data Systems WebHMI | CISA

https://us-cert.cisa.gov/ics/advisories/icsa-21-336-03

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-434Unrestricted Upload of File with Dangerous Type

Data Freshness Timeline

(refreshed 11× in last 7d / 19× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-04 13:10 UTCepss_batch
2026-06-04 13:10 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 06:52 UTCEG score recompute
2026-05-26 06:52 UTCGHSA enrichment

Publicly available exploits

(2 references)

Working exploit code is in the public domain (1 GitHub PoC) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

Exploit-DBEDB-50589
First seen Dec 13, 2021
WebHMI 4.0 - Remote Code Execution (RCE) (Authenticated)
Open source ↗
GitHub PoCLongWayHomie/CVE-2021-43936
First seen Dec 12, 2021
CVE-2021-43936 is a critical vulnerability (CVSS3 10.0) leading to Remote Code Execution (RCE) in WebHMI Firmware.
Open source ↗

Frequently asked(5)

What is CVE-2021-43936?

CVE-2021-43936 is a critical vulnerability published on December 6, 2021. The software allows the attacker to upload or transfer files of dangerous types to the WebHMI portal, that may be automatically processed within the product's environment or lead to arbitrary code execution.

When was CVE-2021-43936 disclosed?

CVE-2021-43936 was first published in the National Vulnerability Database on December 6, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-43936 actively exploited?

CVE-2021-43936 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 96.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-43936?

CVE-2021-43936 has a CVSS v3 base score of 10.0 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.8.

How do I remediate CVE-2021-43936?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-43936, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-43936

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Is Your Infrastructure Affected by CVE-2021-43936?

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CVE-2021-43936

📅 Published

🔄 Last Modified

📋 Advisory Details (1)