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Full vulnerability report · 2021
CVE-2021-22791High confidence

n/a Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions) — Out-of-bounds Write

Unknown · Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions)

6.5MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.84% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Unknown Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions) 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: As exposure requiresRemediation target: Within 365 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-2021-222-04 · CSAF 2.0 · revision 7.0.0 · finalSchneider Electric CPCERTModicon PAC Controllers and PLC Simulator for EcoStruxure™ Control Expert and EcoStruxure™ Process Expert
8 known affected

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

  • Schneider Electric Modicon M580 CPU <SV4.10
  • Schneider Electric Modicon M580 CPU Safety (part numbers BMEP58*S and BMEH58*S) Versions prior to SV4.21
  • Schneider Electric Modicon M340 CPU <3.50
  • Schneider Electric Modicon Momentum CPU All versions <SV2.6
  • Schneider Electric PLC Simulator for EcoStruxure™ Control Expert All versions
  • Schneider Electric PLC Simulator for EcoStruxure™ Process Expert All versions
  • Schneider Electric Legacy Modicon Premium and Quantum All versions
  • Schneider Electric Modicon Premium CPU All versions
Summary
A CWE-787: Out-of-bounds Write vulnerability exists that could cause a Denial of Service on the Modicon PLC controller / simulator when updating the controller application with a specially crafted project file.
Remediation
M340 V3.50 includes a fix for these vulnerabilities and is available for download here: https://www.se.com/ww/en/download/document/BMXP34xxxxx_SV_03.50/
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-2021-9926

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 actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

A CWE-787: Out-of-bounds Write vulnerability that could cause a Denial of Service on the Modicon PLC controller / simulator when updating the controller application with a specially crafted project file exists in Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions).

What

A CWE-787: Out-of-bounds Write vulnerability that could cause a Denial of Service on the Modicon PLC controller / simulator when updating the controller application with a specially crafted project file exists in Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions).

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

What

A CWE-787: Out-of-bounds Write vulnerability that could cause a Denial of Service on the Modicon PLC controller / simulator when updating the controller application with a specially crafted project file exists in Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions).

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

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.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Out-of-bounds Write → disrupt the affected service
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
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-787 ↗

CWE-787: Out-of-bounds Write. The product writes data past the end, or before the beginning, of the intended buffer.

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

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

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkDenial of serviceCWE-787
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-20210908Security Bulletin 08 Sep 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 08 Sep 2021, published on 8 September 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2023-AVI-0273Multiples vulnérabilités dans les produits Schneider

De multiples vulnérabilités ont été découvertes dans les produits Schneider. Elles permettent à un attaquant de provoquer un déni de service à distance.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-717Multiples vulnérabilités dans les produits Schneider

d?id=CVE-2020-35198 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-2021-22786 https://www.cve.org/CVERecord?id=CVE-2021-22786 Référence CVE CVE-2021-22789 https://www.cve.org/CVERecord?id=CVE-2021-22789 Référence CVE CVE-2021-22790 https://www.cve.org/CVERecord?id=CVE-2021-22790 Référence CVE CVE-2021-22791 https://www.cve.org/CVERecord?id=CVE-2021-22791 Référence CVE CVE-2021-22792 https://www.cve.org/CVERecord?id=CVE-2021-22792 Référence CVE CVE-2021-4104 https://www.cve.org/CVERecord?id=CVE-2021-4104 Référence CVE CVE-2021-44228 https://www.cve.org/CVERecord?id=CVE-2021-44228 Référence CVE CVE-2021-44832 https://www.cve.org/CVERecord?id=CVE-2021-44832 Référence CVE CVE-2021-45046 https://www.cve.org/CVERecord?id=CVE-2021-45046 Référence CVE CVE-2021-45105 https://www.cve.org/CVERecord?id=CVE-2021-45105 Référence CVE CVE-2022-34759 https://www.cve.org/CVERecord?id=CVE-2022-34759 Référence CVE CVE-2022-34760 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-1093Multiples vulnérabilités dans les produits Schneider

Record?id=CVE-2019-6846 Référence CVE CVE-2019-6847 https://www.cve.org/CVERecord?id=CVE-2019-6847 Référence CVE CVE-2020-28895 https://www.cve.org/CVERecord?id=CVE-2020-28895 Référence CVE CVE-2020-35198 https://www.cve.org/CVERecord?id=CVE-2020-35198 Référence CVE CVE-2020-6996 https://www.cve.org/CVERecord?id=CVE-2020-6996 Référence CVE CVE-2021-22779 https://www.cve.org/CVERecord?id=CVE-2021-22779 Référence CVE CVE-2021-22786 https://www.cve.org/CVERecord?id=CVE-2021-22786 Référence CVE CVE-2021-22789 https://www.cve.org/CVERecord?id=CVE-2021-22789 Référence CVE CVE-2021-22790 https://www.cve.org/CVERecord?id=CVE-2021-22790 Référence CVE CVE-2021-22791 https://www.cve.org/CVERecord?id=CVE-2021-22791 Référence CVE CVE-2021-22792 https://www.cve.org/CVERecord?id=CVE-2021-22792 Référence CVE CVE-2022-37300 https://www.cve.org/CVERecord?id=CVE-2022-37300 Référence CVE CVE-2022-37301 https://www.cve.org/CVERecord?id=CVE-2022-37301 Référence CVE CVE-2022-4062 https://www.cve.org/CVERecord?id=CVE-2022-4062 Référence CVE CVE-2022-42970 https://www.cve.org/CVERecord?id=CVE-2022-42970 Référence CVE CVE-2022-42971 https://www.cve.org/CVERecord?id=CVE-2022-42971 Référence CVE CVE-2022-42972 https://www.cve.org/CVERecord?id=CVE-2022-42972 Référence CVE CVE-2022-42973 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-622Multiples 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-2021-22704 https://www.cve.org/CVERecord?id=CVE-2021-22704 Référence CVE CVE-2021-22775 https://www.cve.org/CVERecord?id=CVE-2021-22775 Référence CVE CVE-2021-22789 https://www.cve.org/CVERecord?id=CVE-2021-22789 Référence CVE CVE-2021-22790 https://www.cve.org/CVERecord?id=CVE-2021-22790 Référence CVE CVE-2021-22791 https://www.cve.org/CVERecord?id=CVE-2021-22791 Référence CVE CVE-2021-22792 https://www.cve.org/CVERecord?id=CVE-2021-22792 Référence CVE CVE-2021-22793 https://www.cve.org/CVERecord?id=CVE-2021-22793 Référence CVE CVE-2021-30186 https://www.cve.org/CVERecord?id=CVE-2021-30186 Référence CVE CVE-2021-30188 https://www.cve.org/CVERecord?id=CVE-2021-30188 Référence CVE CVE-2021-30195 https://www.cve.org/CVERecord?id=CVE-2021-30195 Référence CVE CVE-2021-31166 https://www.cve.org/CVERecord?id=CVE-2021-31166 Référence CVE CVE-2021-34527 https://www.cve.org/CVERecord?id=CVE-2021-34527 Gestion détaillée du document le 12 août 2021 Version initiale

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-011446複数の Schneider Electric 製品における境界外書き込みに関する脆弱性

複数の Schneider Electric 製品には、境界外書き込み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
M340 V3.50 includes a fix for these vulnerabilities and is available for download here: https://www.se.com/ww/en/download/document/BMXP34xxxxx_SV_03.50/
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 2 Sept 2021 · Last source change 29 May 2026, 13:58 UTC · CWE-787 · Out-of-bounds Write

CVE recordCVE.org · 5.2
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-2021-9926
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
    Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions) · 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
    Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions) · Fixed: M340 V3.50 includes a fix for these vulnerabilities and is available for download here: https://www.se.com/ww/en/download/document/BMXP34xxxxx_SV_03.50/
    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-2021-9926↗Schneider Electric CPCERT security advisory↗Patch or update reference↗CVE authority or vendor 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-2021-22791 · cve.blacktree.nl