CVE-2021-47770Public exploitNetwork attack vector

Authenticated command execution via custom hardware layer

Published Jan 21, 2026 · Updated Jan 21, 2026

Code injection in OpenPLC Runtime v3 allows remote authenticated users to execute commands through the hardware configuration interface. The /hardware workflow accepts attacker-supplied C as custom_layer_code and compiles that code into a selectable custom hardware layer. Valid web credentials and permission to compile and start a PLC program are required; successful payloads run with the Runtime process's privileges.

CVSS severity8.6
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in OpenPLC Runtime v3 allows remote authenticated users to execute commands through the hardware configuration interface. The /hardware workflow accepts attacker-supplied C as custom_layer_code and compiles that code into a selectable custom hardware layer. Valid web credentials and permission to compile and start a PLC program are required; successful payloads run with the Runtime process's privileges.

The record

CVE
CVE-2021-47770
Published
Jan 21, 2026
Updated
Jan 21, 2026
Vendor
OpenPLC Project
Product
OpenPLC Runtime
Classifications
CWE-94, T1190, T1059.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=OpenPLC v3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenPLC Project · OpenPLC Runtimeversion=OpenPLC v3

Published CVSS scores

8.6VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1190Exploit Public-Facing Application
T1059.004Unix Shell

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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