BlackTreeCVE Intelligence
← Back to the CVE catalogue
Full vulnerability report · 2021
CVE-2021-21867High confidence

An unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream.ProfileByteArray functionality of CODESYS GmbH CODESYS Development System 3.5.16 and 3.5.17

Unknown · CODESYS

7.8HighCVSS 3.1
Recommended action
Within 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:High, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • EPSS is 1.65% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Unknown CODESYS and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
SEVD-2022-011-06 · CSAF 2.0 · revision 7.0.0 · finalSchneider Electric CPCERTCODESYS V3 Runtime, Development System, and Gateway Vulnerabilities
2 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • Schneider Electric EcoStruxure Machine Expert version prior to 2.0.3
  • Schneider Electric Eurotherm E+PLC tools version 1.3.0.1 and prior
Summary
Codesys have released a series of vulnerabilities affecting the Codesys Runtime, Development System and Gateway components. Additional details on these vulnerabilities can be found in the CODESYS advisories linked above.
Remediation
V2.0.3 of EcoStruxure Machine Expert includes a fix for these vulnerabilities. On the engineering workstation, update to latest version of EcoStruxure Machine Expert: https://www.se.com/ww/en/product-range/2226-ecostruxure-machine-expert-somachine/?parent-subcategory-id=5140&filter=business-1-industrial-automation-and-control
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-9038

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

An unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream.ProfileByteArray functionality of CODESYS GmbH CODESYS Development System 3.5.16 and 3.5.17. A specially crafted file can lead to arbitrary command execution. An attacker can provide a malicious file to trigger this vulnerability.

What

An unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream.ProfileByteArray functionality of CODESYS GmbH CODESYS Development System 3.5.16 and 3.5.17. A specially crafted file can lead to arbitrary command execution. An attacker can provide a malicious file to trigger this vulnerability.

Why

Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.

How

An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

An unsafe deserialization vulnerability exists in the ObjectManager.plugin ObjectStream.ProfileByteArray functionality of CODESYS GmbH CODESYS Development System 3.5.16 and 3.5.17. A specially crafted file can lead to arbitrary command execution. An attacker can provide a malicious file to trigger this vulnerability.

Why

Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.

How

An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
local access → Deserialization of Untrusted Data → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
None: unauthenticated exploitation is possible
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-502 ↗

CWE-502: Deserialization of Untrusted Data. The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
UnauthenticatedCWE-502Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

Cyber Security Agency of Singapore · English · CSA-SB-20210825Security Bulletin 25 Aug 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 25 Aug 2021, published on 25 August 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-628Multiples vulnérabilités dans les produits Schneider Electric

d?id=CVE-2021-21826 Référence CVE CVE-2021-21827 https://www.cve.org/CVERecord?id=CVE-2021-21827 Référence CVE CVE-2021-21828 https://www.cve.org/CVERecord?id=CVE-2021-21828 Référence CVE CVE-2021-21829 https://www.cve.org/CVERecord?id=CVE-2021-21829 Référence CVE CVE-2021-21830 https://www.cve.org/CVERecord?id=CVE-2021-21830 Référence CVE CVE-2021-21863 https://www.cve.org/CVERecord?id=CVE-2021-21863 Référence CVE CVE-2021-21864 https://www.cve.org/CVERecord?id=CVE-2021-21864 Référence CVE CVE-2021-21865 https://www.cve.org/CVERecord?id=CVE-2021-21865 Référence CVE CVE-2021-21866 https://www.cve.org/CVERecord?id=CVE-2021-21866 Référence CVE CVE-2021-21867 https://www.cve.org/CVERecord?id=CVE-2021-21867 Référence CVE CVE-2021-21868 https://www.cve.org/CVERecord?id=CVE-2021-21868 Référence CVE CVE-2021-21869 https://www.cve.org/CVERecord?id=CVE-2021-21869 Référence CVE CVE-2021-22778 https://www.cve.org/CVERecord?id=CVE-2021-22778 Référence CVE CVE-2021-22779 https://www.cve.org/CVERecord?id=CVE-2021-22779 Référence CVE CVE-2021-22780 https://www.cve.org/CVERecord?id=CVE-2021-22780 Référence CVE CVE-2021-22781 https://www.cve.org/CVERecord?id=CVE-2021-22781 Référence CVE CVE-2021-22782 https://www.cve.org/CVERecord?id=CVE-2021-22782 Référence CVE CVE-2021-22797 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-017Multiples vulnérabilités dans les produits Schneider

022-011-07 du 11 janvier 2022 https://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2022-011-07 Référence CVE CVE-2019-8963 https://www.cve.org/CVERecord?id=CVE-2019-8963 Référence CVE CVE-2020-7534 https://www.cve.org/CVERecord?id=CVE-2020-7534 Référence CVE CVE-2020-8597 https://www.cve.org/CVERecord?id=CVE-2020-8597 Référence CVE CVE-2021-21863 https://www.cve.org/CVERecord?id=CVE-2021-21863 Référence CVE CVE-2021-21864 https://www.cve.org/CVERecord?id=CVE-2021-21864 Référence CVE CVE-2021-21865 https://www.cve.org/CVERecord?id=CVE-2021-21865 Référence CVE CVE-2021-21866 https://www.cve.org/CVERecord?id=CVE-2021-21866 Référence CVE CVE-2021-21867 https://www.cve.org/CVERecord?id=CVE-2021-21867 Référence CVE CVE-2021-21868 https://www.cve.org/CVERecord?id=CVE-2021-21868 Référence CVE CVE-2021-21869 https://www.cve.org/CVERecord?id=CVE-2021-21869 Référence CVE CVE-2021-29240 https://www.cve.org/CVERecord?id=CVE-2021-29240 Référence CVE CVE-2021-29241 https://www.cve.org/CVERecord?id=CVE-2021-29241 Référence CVE CVE-2021-30061 https://www.cve.org/CVERecord?id=CVE-2021-30061 Référence CVE CVE-2021-30062 https://www.cve.org/CVERecord?id=CVE-2021-30062 Référence CVE CVE-2021-30063 https://www.cve.org/CVERecord?id=CVE-2021-30063 Référence CVE CVE-2021-30064 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-010847CODESYS GmbH CODESYS Development System における信頼できないデータのデシリアライゼーションに関する脆弱性

CODESYS GmbH CODESYS Development System には、信頼できないデータのデシリアライゼーションに関する脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
Action
V2.0.3 of EcoStruxure Machine Expert includes a fix for these vulnerabilities. On the engineering workstation, update to latest version of EcoStruxure Machine Expert: https://www.se.com/ww/en/product-range/2226-ecostruxure-machine-expert-somachine/?parent-subcategory-id=5140&filter=business-1-industrial-automation-and-control
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 18 Aug 2021 · Last source change 3 Aug 2024, 18:23 UTC · CWE-502 · Deserialization of Untrusted Data

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-9038
Product sourceVendor CSAF · Schneider Electric CPCERT
Remediation sourceVendor CSAF · Schneider Electric CPCERT
CWE sourceCNA
NVD statusNVD modified after enrichment

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    CODESYS GmbH CODESYS Development System 3.5.16, CODESYS GmbH CODESYS Development System 3.5.17 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    CODESYS GmbH CODESYS Development System 3.5.16, CODESYS GmbH CODESYS Development System 3.5.17 · Fixed: V2.0.3 of EcoStruxure Machine Expert includes a fix for these vulnerabilities. On the engineering workstation, update to latest version of EcoStruxure Machine Expert: https://www.se.com/ww/en/product-range/2226-ecostruxure-machine-expert-somachine/?parent-subcategory-id=5140&filter=business-1-industrial-automation-and-control
    Schneider Electric CPCERT ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2021-9038↗Schneider Electric CPCERT security advisory↗Patch or update reference↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-21867 · cve.blacktree.nl