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Full vulnerability report · 2020
CVE-2020-7565High confidence

n/a Modicon M221, all references, all versions — Inadequate Encryption Strength

n/a · Modicon M221, all references, all versions

7.3HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Mitigation available
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-2020-315-05 · CSAF 2.0 · revision 3.0.0 · finalSchneider Electric CPCERTModicon M100/M200/M221 Programmable Logic Controller
3 known affected

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

  • Schneider Electric Modicon M100 all references all versions
  • Schneider Electric Modicon M200 all references all versions
  • Schneider Electric Modicon M221 all references all versions
Summary
CWE-326: Inadequate Encryption Strength vulnerability exists that could allow the attacker to break the encryption key when the attacker has captured the traffic between EcoStruxure Machine - Basic software and Modicon M100/M200/M221 controllers.
Remediation
Customers should immediately apply the following mitigations to reduce the risk of exploit: • Setup network segmentation and implement a firewall to block all unauthorized access to port 502/TCP. • Within the Modicon M100/M200/M221 application, the user must: o Disable all unused protocols, especially Programming protocol, as described in section "Configuring Ethernet Network" of EcoStruxure Machine Expert - Basic online help for the M100/M200/M221 PLCs. This action will prevent unintended remote programming access. o Set a password to protect the project o Set a password for read access on the controller o Set a different password for write access on the controller
Optional official sources

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

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

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-2020-28690

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.

Mitigation available
01

What, why and how

A CWE-326: Inadequate Encryption Strength vulnerability exists in Modicon M221 (all references, all versions) that could allow the attacker to break the encryption key when the attacker has captured the traffic between EcoStruxure Machine - Basic software and Modicon M221 controller.

What

A CWE-326: Inadequate Encryption Strength vulnerability exists in Modicon M221 (all references, all versions) that could allow the attacker to break the encryption key when the attacker has captured the traffic between EcoStruxure Machine - Basic software and Modicon M221 controller.

Why

The product stores or transmits sensitive data using an encryption scheme that is theoretically sound, but is not strong enough for the level of protection required.

How

An attacker operating through the affected interface 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

A CWE-326: Inadequate Encryption Strength vulnerability exists in Modicon M221 (all references, all versions) that could allow the attacker to break the encryption key when the attacker has captured the traffic between EcoStruxure Machine - Basic software and Modicon M221 controller.

Why

The product stores or transmits sensitive data using an encryption scheme that is theoretically sound, but is not strong enough for the level of protection required.

How

An attacker operating through the affected interface 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.
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
the affected interface → Inadequate Encryption Strength → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Unspecified
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-326 ↗

CWE-326: Inadequate Encryption Strength. The product stores or transmits sensitive data using an encryption scheme that is theoretically sound, but is not strong enough for the level of protection required.

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

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

AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.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.ANoneAvailability impact: No direct loss is represented by this metric.
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.
UnauthenticatedCWE-326
A

Official authority intelligence

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

CERT-FR · French · CERTFR-2020-AVI-726Multiples vulnérabilités dans les produits Schneider Electric

.cve.org/CVERecord?id=CVE-2020-7555 Référence CVE CVE-2020-7556 https://www.cve.org/CVERecord?id=CVE-2020-7556 Référence CVE CVE-2020-7557 https://www.cve.org/CVERecord?id=CVE-2020-7557 Référence CVE CVE-2020-7558 https://www.cve.org/CVERecord?id=CVE-2020-7558 Référence CVE CVE-2020-7559 https://www.cve.org/CVERecord?id=CVE-2020-7559 Référence CVE CVE-2020-7561 https://www.cve.org/CVERecord?id=CVE-2020-7561 Référence CVE CVE-2020-7562 https://www.cve.org/CVERecord?id=CVE-2020-7562 Référence CVE CVE-2020-7563 https://www.cve.org/CVERecord?id=CVE-2020-7563 Référence CVE CVE-2020-7564 https://www.cve.org/CVERecord?id=CVE-2020-7564 Référence CVE CVE-2020-7565 https://www.cve.org/CVERecord?id=CVE-2020-7565 Référence CVE CVE-2020-7566 https://www.cve.org/CVERecord?id=CVE-2020-7566 Référence CVE CVE-2020-7567 https://www.cve.org/CVERecord?id=CVE-2020-7567 Référence CVE CVE-2020-7570 https://www.cve.org/CVERecord?id=CVE-2020-7570 Référence CVE CVE-2020-7571 https://www.cve.org/CVERecord?id=CVE-2020-7571 Référence CVE CVE-2020-7572 https://www.cve.org/CVERecord?id=CVE-2020-7572 Gestion détaillée du document le 12 novembre 2020 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales À propos Contact cyber.gouv.fr service-public.fr legifrance.gouv.fr info.gouv.fr franc

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.
Mitigation available
Affected
Schneider Electric Modicon M100 all references all versions; Schneider Electric Modicon M200 all references all versions; Schneider Electric Modicon M221 all references all versions
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
Customers should immediately apply the following mitigations to reduce the risk of exploit: • Setup network segmentation and implement a firewall to block all unauthorized access to port 502/TCP. • Within the Modicon M100/M200/M221 application, the user must: o Disable all unused protocols, especially Programming protocol, as described in section "Configuring Ethernet Network" of EcoStruxure Machine Expert - Basic online help for the M100/M200/M221 PLCs. This action will prevent unintended remote programming access. o Set a password to protect the project o Set a password for read access on the controller o Set a different password for write access on the controller
04

Evidence and provenance

Published 19 Nov 2020 · Last source change 29 May 2026, 13:28 UTC · CWE-326 · Inadequate Encryption Strength

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-2020-28690
Product sourceVendor CSAF · Schneider Electric CPCERT
Remediation sourceVendor CSAF · Schneider Electric CPCERT
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2020-28690↗Vendor CSAF · Schneider Electric CPCERT↗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-2020-7565 · cve.blacktree.nl