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Full vulnerability report · 2022
CVE-2021-22800High confidence

A CWE-20: Improper Input Validation vulnerability exists that could cause a Denial of Service when a crafted packet is sent to the controller over network port 1105/TCP

Unknown · Modicon M218 Logic Controller (V5.1.0.6 and prior)

7.5HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; 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.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 1.00% 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 M218 Logic Controller (V5.1.0.6 and prior) 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-2021-285-04 · CSAF 2.0 · revision 1.0.0 · finalSchneider Electric CPCERTModicon M218 Logic Controller
1 known affected

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

  • Schneider Electric Modicon M218 logic controller v5.1.0.6 and prior
Summary
A CWE-20: Improper Input Validation vulnerability exists that could cause a Denial of Service when a crafted packet is sent to the controller over network port 1105/TCP.
Remediation
Version 5.1.0.8 of the Modicon M218 logic controller product includes a fix for this vulnerability. • On the engineering workstation, update to EcoStruxure Machine Expert v2.0.1 or above: https://www.se.com/ww/en/product-range-download/2226-ecostruxure-machine-expert-%28somachine%29/?selected-node-id=14435955187#/software-firmware-tab • On Modicon M218 logic controller, update to latest firmware version available within EcoStruxure Machine Expert v2.0.1 or above. A reboot of the controller is needed
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-2021-9935

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; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

A CWE-20: Improper Input Validation vulnerability exists that could cause a Denial of Service when a crafted packet is sent to the controller over network port 1105/TCP. Affected Product: Modicon M218 Logic Controller (V5.1.0.6 and prior)

What

A CWE-20: Improper Input Validation vulnerability exists that could cause a Denial of Service when a crafted packet is sent to the controller over network port 1105/TCP. Affected Product: Modicon M218 Logic Controller (V5.1.0.6 and prior)

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

A CWE-20: Improper Input Validation vulnerability exists that could cause a Denial of Service when a crafted packet is sent to the controller over network port 1105/TCP. Affected Product: Modicon M218 Logic Controller (V5.1.0.6 and prior)

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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 → Improper Input Validation → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
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-20 ↗

CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

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:N/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.PRNonePrivileges required: The attacker does not need an account or existing 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.
NetworkUnauthenticatedDenial of serviceCWE-20
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-20220216Security Bulletin 16 Feb 2022

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 16 Feb 2022, published on 16 February 2022. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-772Multiples vulnérabilités dans les produits Schneider

.org/CVERecord?id=CVE-2020-0609 Référence CVE CVE-2020-0610 https://www.cve.org/CVERecord?id=CVE-2020-0610 Référence CVE CVE-2020-0796 https://www.cve.org/CVERecord?id=CVE-2020-0796 Référence CVE CVE-2020-0938 https://www.cve.org/CVERecord?id=CVE-2020-0938 Référence CVE CVE-2020-1020 https://www.cve.org/CVERecord?id=CVE-2020-1020 Référence CVE CVE-2020-1350 https://www.cve.org/CVERecord?id=CVE-2020-1350 Référence CVE CVE-2020-13987 https://www.cve.org/CVERecord?id=CVE-2020-13987 Référence CVE CVE-2020-1472 https://www.cve.org/CVERecord?id=CVE-2020-1472 Référence CVE CVE-2020-17438 https://www.cve.org/CVERecord?id=CVE-2020-17438 Référence CVE CVE-2021-22800 https://www.cve.org/CVERecord?id=CVE-2021-22800 Référence CVE CVE-2021-22801 https://www.cve.org/CVERecord?id=CVE-2021-22801 Référence CVE CVE-2021-22802 https://www.cve.org/CVERecord?id=CVE-2021-22802 Référence CVE CVE-2021-22803 https://www.cve.org/CVERecord?id=CVE-2021-22803 Référence CVE CVE-2021-22804 https://www.cve.org/CVERecord?id=CVE-2021-22804 Référence CVE CVE-2021-22805 https://www.cve.org/CVERecord?id=CVE-2021-22805 Référence CVE CVE-2021-22806 https://www.cve.org/CVERecord?id=CVE-2021-22806 Gestion détaillée du document le 12 octobre 2021 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-018353Modicon M218 Logic Controller における入力確認に関する脆弱性

Modicon M218 Logic Controller には、入力確認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
Schneider Electric Modicon M218 logic controller v5.1.0.6 and prior
Fixed
Schneider Electric Modicon M218 logic controller 5.1.0.8
Action
Version 5.1.0.8 of the Modicon M218 logic controller product includes a fix for this vulnerability. • On the engineering workstation, update to EcoStruxure Machine Expert v2.0.1 or above: https://www.se.com/ww/en/product-range-download/2226-ecostruxure-machine-expert-%28somachine%29/?selected-node-id=14435955187#/software-firmware-tab • On Modicon M218 logic controller, update to latest firmware version available within EcoStruxure Machine Expert v2.0.1 or above. A reboot of the controller is needed
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 11 Feb 2022 · Last source change 3 Aug 2024, 18:51 UTC · CWE-20 · Improper Input Validation

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-2021-9935
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 M218 Logic Controller (V5.1.0.6 and prior) · 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 M218 Logic Controller (V5.1.0.6 and prior) · Fixed: Version 5.1.0.8 of the Modicon M218 logic controller product includes a fix for this vulnerability. • On the engineering workstation, update to EcoStruxure Machine Expert v2.0.1 or above: https://www.se.com/ww/en/product-range-download/2226-ecostruxure-machine-expert-%28somachine%29/?selected-node-id=14435955187#/software-firmware-tab • On Modicon M218 logic controller, update to latest firmware version available within EcoStruxure Machine Expert v2.0.1 or above. A reboot of the controller is needed
    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-2021-9935↗Schneider Electric CPCERT security advisory↗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-2021-22800 · cve.blacktree.nl