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Full vulnerability report · 2021
CVE-2021-22735High confidence

n/a homeLYnk (Wiser For KNX) and spaceLYnk V2.60 and prior — Improper Verification of Cryptographic Signature

Unknown · homeLYnk (Wiser For KNX) and spaceLYnk V2.60 and prior

7.2HighCVSS 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.
  • 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 homeLYnk (Wiser For KNX) and spaceLYnk V2.60 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-2021-130-04 · CSAF 2.0 · revision 2 · finalSchneider Electric CPCERThomeLYnk (Wiser For KNX) and spaceLYnk
2 known affected

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

  • Schneider Electric homeLYnk (Wiser For KNX) versions 2.60 and prior
  • Schneider Electric spaceLYnk versions 2.60 and prior
Summary
A CWE-347: Improper Verification of Cryptographic Signature vulnerability exists that could allow remote code execution when unauthorized code is copied to the device.
Remediation
Version 2.61 of homeLYnk (Wiser For KNX) and spaceLYnk include a fix for these vulnerabilities and are available for download below: homeLYnk (Wiser For KNX) V2.61 - https://www.se.com/ww/en/product/LSS100100/wiser-for-knx-logiccontroller/#pdp-software spaceLYnk V2.61 - https://www.se.com/ww/en/product/LSS100200/spacelynk-logiccontroller/#pdp-software Note: Reboot is needed after installation. Please check the version number in the configuration to confirm the update.
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-2021-9870

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

Improper Verification of Cryptographic Signature vulnerability exists inhomeLYnk (Wiser For KNX) and spaceLYnk V2.60 and prior which could allow remote code execution when unauthorized code is copied to the device.

What

Improper Verification of Cryptographic Signature vulnerability exists inhomeLYnk (Wiser For KNX) and spaceLYnk V2.60 and prior which could allow remote code execution when unauthorized code is copied to the device.

Why

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.

What

Improper Verification of Cryptographic Signature vulnerability exists inhomeLYnk (Wiser For KNX) and spaceLYnk V2.60 and prior which could allow remote code execution when unauthorized code is copied to the device.

Why

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.

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 Verification of Cryptographic Signature → execute code or commands in the affected security context
Attack surface
Network
Privileges required
High: elevated access 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-347 ↗

CWE-347: Improper Verification of Cryptographic Signature. The product does not verify, or incorrectly verifies, the cryptographic signature for data.

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:H/UI:N/S:U/C:H/I:H/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.PRHighPrivileges required: The attacker needs elevated or administrative 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.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
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkRemote code executionCWE-347
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-20210602Security Bulletin 02 Jun 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 02 Jun 2021, published on 2 June 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-370Multiples vulnérabilités dans les produits Schneider

ecord?id=CVE-2020-10245 Référence CVE CVE-2020-6081 https://www.cve.org/CVERecord?id=CVE-2020-6081 Référence CVE CVE-2020-7052 https://www.cve.org/CVERecord?id=CVE-2020-7052 Référence CVE CVE-2021-22699 https://www.cve.org/CVERecord?id=CVE-2021-22699 Référence CVE CVE-2021-22705 https://www.cve.org/CVERecord?id=CVE-2021-22705 Référence CVE CVE-2021-22731 https://www.cve.org/CVERecord?id=CVE-2021-22731 Référence CVE CVE-2021-22732 https://www.cve.org/CVERecord?id=CVE-2021-22732 Référence CVE CVE-2021-22733 https://www.cve.org/CVERecord?id=CVE-2021-22733 Référence CVE CVE-2021-22734 https://www.cve.org/CVERecord?id=CVE-2021-22734 Référence CVE CVE-2021-22735 https://www.cve.org/CVERecord?id=CVE-2021-22735 Référence CVE CVE-2021-22736 https://www.cve.org/CVERecord?id=CVE-2021-22736 Référence CVE CVE-2021-22737 https://www.cve.org/CVERecord?id=CVE-2021-22737 Référence CVE CVE-2021-22738 https://www.cve.org/CVERecord?id=CVE-2021-22738 Référence CVE CVE-2021-22739 https://www.cve.org/CVERecord?id=CVE-2021-22739 Référence CVE CVE-2021-22740 https://www.cve.org/CVERecord?id=CVE-2021-22740 Référence CVE CVE-2021-22741 https://www.cve.org/CVERecord?id=CVE-2021-22741 Référence CVE CVE-2021-22742 https://www.cve.org/CVERecord?id=CVE-2021-22742 Référence CVE CVE-2021-22743 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-007525homeLYnk および spaceLYnk におけるデジタル署名の検証に関する脆弱性

homeLYnk (Wiser For KNX) および spaceLYnk には、デジタル署名の検証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
Version 2.61 of homeLYnk (Wiser For KNX) and spaceLYnk include a fix for these vulnerabilities and are available for download below: homeLYnk (Wiser For KNX) V2.61 - https://www.se.com/ww/en/product/LSS100100/wiser-for-knx-logiccontroller/#pdp-software spaceLYnk V2.61 - https://www.se.com/ww/en/product/LSS100200/spacelynk-logiccontroller/#pdp-software Note: Reboot is needed after installation. Please check the version number in the configuration to confirm the update.
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 26 May 2021 · Last source change 3 Aug 2024, 18:51 UTC · CWE-347 · Improper Verification of Cryptographic Signature

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-2021-9870
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
    homeLYnk (Wiser For KNX) and spaceLYnk V2.60 and prior · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    homeLYnk (Wiser For KNX) and spaceLYnk V2.60 and prior · Fixed: Version 2.61 of homeLYnk (Wiser For KNX) and spaceLYnk include a fix for these vulnerabilities and are available for download below: homeLYnk (Wiser For KNX) V2.61 - https://www.se.com/ww/en/product/LSS100100/wiser-for-knx-logiccontroller/#pdp-software spaceLYnk V2.61 - https://www.se.com/ww/en/product/LSS100200/spacelynk-logiccontroller/#pdp-software Note: Reboot is needed after installation. Please check the version number in the configuration to confirm the update.
    Schneider Electric CPCERT ↗
  2. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    Schneider Electric CPCERT ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2021-9870↗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-2021-22735 · cve.blacktree.nl