CVE-2021-43936WebHMI Unrestricted File Upload
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.
Published Dec 6, 2021 · Updated Nov 21, 2024
Key Facts
Patch immediately- CVE-2021-43936 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Webhmi Firmware, WebHMI.
- It is exploited in the wild, listed in Industry KEV feed since May 9, 2024. Public exploit code is available.
- EPSS estimates a 36% probability of exploitation in the next 30 days.
- Fixed versions are available, including WebHMI 4.1, Webhmi Firmware 4.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
36%
Higher than 98.4% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
41/100
Publication score, see How it works
Exploitation Verdict
KEV listed
May 9, 2024
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Proof of concept
Public exploit code
2
Proof-of-concept links
In-the-wild evidence
7
Reports of active use
Advisories And Exploit References
Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | May 9, 2024 | n/a | Not reported |
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Webhmi FirmwareWebhmi | See advisory | 4.1 |
| WebHMI | >= 4.1 | 4.1 |
Patched Releases
WebHMI
4.1
Webhmi Firmware
4.1
Timeline
Publicly disclosed
Dec 6, 2021
Added to Industry KEV feed
May 9, 2024
Last updated
Nov 21, 2024
Weakness Type
- CWE-434 Unrestricted Upload of File with Dangerous Type
References
- patchus-cert.cisa.gov · icsa-21-336-03
- exploitpacketstormsecurity.com · WebHMI-4.0-Remote-Code-Execution.html
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
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.
Affected: Webhmi Firmware; WebHMI versions >= 4.1. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since May 9, 2024.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including WebHMI 4.1, Webhmi Firmware 4.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2021-43936 On Your Attack Surface?
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