Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.73% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2020
CVE-2020-28214High confidence
n/a Modicon M221 (all references, all versions) — Use of a One-Way Hash with a Predictable Salt
Unknown · Modicon M221 (all references, all versions)
5.5MediumCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 3 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Low, lowered one band.downgradedsince 28 May 2026
Compensating controls
- Apply the linked authoritative mitigation while planning the permanent fix.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown Modicon M221 (all references, all versions) and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 3 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Schneider Electric CPCERT: 3 affected or under-investigation product states without a fixed product state in the same current advisory
Direct vendor intelligence
1 currentAuthoritative 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.
SEVD-2020-315-05 · CSAF 2.0 · revision 3.0.0 · finalSchneider Electric CPCERTModicon M100/M200/M221 Programmable Logic Controller
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-760: Use of a One-Way Hash with a Predictable Salt vulnerability exists that could allow an attacker to pre-compute the hash value using dictionary attack technique such as rainbow tables, effectively disabling the protection that an unpredictable salt would provide.
- 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
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 3 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
A CWE-760: Use of a One-Way Hash with a Predictable Salt vulnerability exists in Modicon M221 (all references, all versions), that could allow an attacker to pre-compute the hash value using dictionary attack technique such as rainbow tables, effectively disabling the protection that an unpredictable salt would provide.
What
A CWE-760: Use of a One-Way Hash with a Predictable Salt vulnerability exists in Modicon M221 (all references, all versions), that could allow an attacker to pre-compute the hash value using dictionary attack technique such as rainbow tables, effectively disabling the protection that an unpredictable salt would provide.
Why
The product uses a one-way cryptographic hash against an input that should not be reversible, such as a password, but the product uses a predictable salt as part of the input.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
A CWE-760: Use of a One-Way Hash with a Predictable Salt vulnerability exists in Modicon M221 (all references, all versions), that could allow an attacker to pre-compute the hash value using dictionary attack technique such as rainbow tables, effectively disabling the protection that an unpredictable salt would provide.
Why
The product uses a one-way cryptographic hash against an input that should not be reversible, such as a password, but the product uses a predictable salt as part of the input.
How
An attacker operating through local access may attempt exploitation with low privileges. 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 No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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
- local access → Use of a One-Way Hash with a Predictable Salt → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Local
- 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-760 ↗
CWE-760: Use of a One-Way Hash with a Predictable Salt. The product uses a one-way cryptographic hash against an input that should not be reversible, such as a password, but the product uses a predictable salt as part of the input.
- 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:L/UI:N/S:U/C:H/I:N/A:NCommon 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.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.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.- 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.
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. - Fix availability varies by product
- Affected
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- 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 11 Dec 2020 · Last source change 28 May 2026, 20:12 UTC · CWE-760 · Use of a One-Way Hash with a Predictable Salt
CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2020-20698
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
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
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.