CVE-2020-6081Public exploitNetwork attack vector

Remote code execution via CRC-only application validation

Published May 7, 2020 · Updated Aug 4, 2024

Code execution in PLC_Task in CODESYS Runtime 3.5.14.30 allows remote authenticated users to run native code via an application upload. The runtime applies only a CRC32 check to uploaded native machine code, then executes it in a codesys3 thread without verifying a cryptographic signature. Project-upload access over SSH or TCP port 11740 is required, but disabled runtime authentication exposes the same code execution without credentials.

CVSS severity8.8
High
EPSS probability1.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code execution in PLC_Task in CODESYS Runtime 3.5.14.30 allows remote authenticated users to run native code via an application upload. The runtime applies only a CRC32 check to uploaded native machine code, then executes it in a codesys3 thread without verifying a cryptographic signature. Project-upload access over SSH or TCP port 11740 is required, but disabled runtime authentication exposes the same code execution without credentials.

The record

CVE
CVE-2020-6081
Published
May 7, 2020
Updated
Aug 4, 2024
Vendor
CODESYS GmbH
Product
CODESYS Runtime
Classifications
CWE-345, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 7, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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=3S-Smart Software Solutions GmbH CODESYS Runtime 3.5.14.30

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

CODESYS GmbH · CODESYS Runtimeversion=3S-Smart Software Solutions GmbH CODESYS Runtime 3.5.14.30

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
9.9Cisco TalosCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/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-345Insufficient Verification of Data Authenticity
T1190Exploit Public-Facing Application

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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