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NVD / CVE Program· CNA CERTVDE

CVE-2023-3669: CODESYS: Missing Brute-Force protection in CODESYS Development System

Noroxi assessment

Priority: Monitor (action score 13/100)

  • 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: 0.14% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: CODESYS CODESYS Development System 3.5.19.20.

Low priority for now. Upgrade to CODESYS CODESYS Development System 3.5.19.20 or later.

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

A missing Brute-Force protection in CODESYS Development System prior to 3.5.19.20 allows a local attacker to have unlimited attempts of guessing the password within an import dialog.

LowCVSS 3.3 · v3.1—No exploit Fix available
Published
Aug 3, 2023
Updated
Jun 17, 2026
EPSS
0.1% · 4th percentile

Report tools

JSON

Action score

13

Monitor

Low priority for now.

CVSS
13 / 40 · 3.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · CERTVDE
3.3
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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

Follow CVE-2023-3669

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
codesysdevelopment system

Affected versions

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

  • codesys development systembefore 3.5.19.20

Versions reported by the vendor

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

  • CODESYS CODESYS Development System

    • 3.0.0.0 and later · before 3.5.19.20affected · semver

Same product

codesys: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-3663CODESYS: Missing integrity check in CODESYS Development System
    35Monitor
  • CVE-2026-44469Incorrect Default Permissions in CODESYS Development System
    34Monitor
  • CVE-2026-44468Incorrect Default Permissions in CODESYS Development System
    34Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2022-31805Jun 24, 2022 · Insecure transmission of credentials
    30Monitor
  • ← EarlierCVE-2023-3670Jul 28, 2023 · Codesys: Vulnerability in CODESYS Development System and CODESYS Scripting
    29Monitor
  • ← EarlierCVE-2023-3662Aug 3, 2023 · CODESYS: Vulnerability in CODESYS Development System allows for execution of binaries
    29Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
CODESYS CODESYS Development System3.5.19.20Vendor (CNA)

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
none
Availability
none
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-307 · Improper Restriction of Excessive Authentication Attempts

CVSS vector

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

nvd-secondary

Attack context

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

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

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

All records