CVE-2021-20836

Code execution via malformed SCS project file

Published Oct 19, 2021 · Updated Aug 3, 2024

Out-of-bounds read in OMRON CX-Supervisor 4.0.0.13 and 4.0.0.16 allows local users to execute code via crafted SCS project files. During SCS project-file processing, the application reads beyond a buffer boundary; public advisories do not identify the malformed field or omitted bounds check. Exploitation requires administrative access to change system settings and user interaction to open the file; successful processing executes code or discloses information.

CVSS severity6.5
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in OMRON CX-Supervisor 4.0.0.13 and 4.0.0.16 allows local users to execute code via crafted SCS project files. During SCS project-file processing, the application reads beyond a buffer boundary; public advisories do not identify the malformed field or omitted bounds check. Exploitation requires administrative access to change system settings and user interaction to open the file; successful processing executes code or discloses information.

The record

CVE
CVE-2021-20836
Published
Oct 19, 2021
Updated
Aug 3, 2024
Vendor
OMRON Corporation
Product
CX-Supervisor
Classifications
CWE-125, T1203, T1204.002
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 19, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=v4.0.0.13 and v4.0.0.16

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

OMRON Corporation · CX-Supervisorversion=v4.0.0.13 and v4.0.0.16

Published CVSS scores

6.0NIST NVDAV:N/AC:M/Au:S/C:P/I:P/A:P
6.5JPCERT/CCCVSS:3.0/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
6.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:R/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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1203Exploitation for Client Execution
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

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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