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NVD / CVE Program· CNA jpcert

CVE-2021-20836: Out-of-bounds read vulnerability in CX-Supervisor v4.0.0.13 and v4.0.0.16 allows an attacker with administrative privileges to cause…

Noroxi assessment

Priority: Monitor (action score 26/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.80% (FIRST EPSS); higher than 57.1% of all records.
  • Someone with local access to the system can trigger it. Administrator privileges are required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Out-of-bounds read vulnerability in CX-Supervisor v4.0.0.13 and v4.0.0.16 allows an attacker with administrative privileges to cause information disclosure and/or arbitrary code execution by opening a specially crafted SCS project files.

MediumCVSS 6.5 · v3.1—No exploit No fix recorded
Published
Oct 18, 2021
Updated
Jun 16, 2026
EPSS
0.8% · 57th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.8%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-20836

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
omroncx-supervisor

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • omron cx-supervisor4.0.0.13
  • omron cx-supervisor4.0.0.16

Versions reported by the vendor

Affected version ranges reported by the assigning authority (jpcert). Independent of NVD's CPE analysis and usually ahead of it.

  • OMRON Corporation OMRON CX-Supervisor

    • v4.0.0.13 and v4.0.0.16affected

Same product

omron: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-18251In Omron CX-Supervisor, Versions 3.5 (12) and prior, Omron CX-Supervisor ships with Teamviewer Version 5.0.8703 QS.
    36Monitor
  • CVE-2018-19017Several use after free vulnerabilities have been identified in CX-Supervisor (Versions 3.42 and prior).
    36Monitor
  • CVE-2018-19011CX-Supervisor (Versions 3.42 and prior) can execute code that has been injected into a project file.
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2018-19015Jan 28, 2019 · An attacker could inject commands to launch programs and create, write, and read files on CX-Supervisor (Versions 3.42 and prior) through a…
    29Monitor
  • ← EarlierCVE-2018-19018Feb 12, 2019 · An access of uninitialized pointer vulnerability in CX-Supervisor (Versions 3.42 and prior) could lead to type confusion when processing…
    29Monitor
  • ← EarlierCVE-2018-19020Feb 12, 2019 · When CX-Supervisor (Versions 3.42 and prior) processes project files and tampers with the value of an offset, an attacker can force the…
    20Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • Administrator privileges are required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
High
User interaction
Required
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records