BlackTreeCVE Intelligence
← Back to the CVE catalogue
Full vulnerability report · 2023
CVE-2023-23451High confidence

The Flexi Classic and Flexi Soft Gateways SICK UE410-EN3 FLEXI ETHERNET GATEW

Unknown · SICK FX0-GENT00000, SICK FX0-GENT00030, SICK FX0-GMOD00000, SICK FX0-GMOD00010, SICK FX0-GPNT00000, SICK FX0-GPNT00030, SICK UE410-EN1, SICK UE410-EN3, SICK UE410-EN3S04, SICK UE410-EN4

9.8CriticalCVSS 3.1
Recommended action
Within 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, 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 0.62% 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 SICK FX0-GENT00000, SICK FX0-GENT00030, SICK FX0-GMOD00000, SICK FX0-GMOD00010, SICK FX0-GPNT00000, SICK FX0-GPNT00030, SICK UE410-EN1, SICK UE410-EN3, SICK UE410-EN3S04, SICK UE410-EN4 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 3 daysRemediation target: Within 90 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
SCA-2023-0002 · CSAF 2.0 · revision 2 · finalSICK PSIRTUse of Telnet in multiple SICK Flexi Soft and Flexi Classic Gateways
10 known affected

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

  • SICK UE410-EN3 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions
  • SICK UE410-EN1 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions
  • SICK UE410-EN3S04 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions
  • SICK UE410-EN4 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions
  • SICK FX0-GENT00000 FLEXISOFT EIP GATEW. with serial number <=2311xxxx with Firmware <=V2.11.0
  • SICK FX0-GMOD00000 FLEXISOFT MOD GATEW. with serial number <=2311xxxx with Firmware <=V2.11.0
  • SICK FX0-GPNT00000 FLEXISOFT PNET GATEW. with serial number <=2311xxxx with Firmware <=V2.12.0
  • SICK FX0-GENT00030 FLEXISOFT EIP GATEW.V2 with serial number <=2311xxxx all Firmware versions
  • SICK FX0-GPNT00030 FLEXISOFT PNET GATEW.V2 with serial number <=2311xxxx all Firmware versions
  • SICK FX0-GMOD00010 FLEXISOFT MOD GW (C) with serial number <=2311xxxx with Firmware <=V2.11.0
Summary
If the default password is not changed by the operator or customer, a remote unauthorized adversary may connect to the Flexi Soft Gateway via Telnet, interact with the device and change settings of the Gateway. The adversary may also reset the Gateway and in the worst case upload a new firmware version to the device that is then run under root privileges. SICK recommends to set a strong device individual password once the product is put into operation.
Remediation
SICK recommends to set a strong password for the Telnet protocol once the Gateway is put into operation. It is possible to set a password with a maximum length of 15 characters. Enter the following commands to change the Telnet password: ```bash $ telnet Password: [Enter] passwd quit [Enter] $ telnet Password: [Enter] ``` Test if [Enter] still works and if the new password is saved.
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-2023-27551

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 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
01

What, why and how

The Flexi Classic and Flexi Soft Gateways SICK UE410-EN3 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK UE410-EN1 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK UE410-EN3S04 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK UE410-EN4 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK FX0-GENT00000 FLEXISOFT EIP GATEW. with serial number <=2311xxxx with Firmware <=V2.11.0, SICK FX0-GMOD00000 FLEXISOFT MOD GATEW. with serial number <=2311xxxx with Firmware <=V2.11.0, SICK FX0-GPNT00000 FLEXISOFT PNET GATEW. with serial number <=2311xxxx with Firmware <=V2.12.0, SICK FX0-GENT00030 FLEXISOFT EIP GATEW.V2 with serial number <=2311xxxx all Firmware versions, SICK FX0-GPNT00030 FLEXISOFT PNET GATEW.V2 with serial number <=2311xxxx all Firmware versions and SICK FX0-GMOD00010 FLEXISOFT MOD GW with serial number <=2311xxxx with Firmware <=V2.11.0 all have Telnet enabled by factory default. No password is set in the default configuration.

What

The Flexi Classic and Flexi Soft Gateways SICK UE410-EN3 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK UE410-EN1 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK UE410-EN3S04 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK UE410-EN4 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK FX0-GENT00000 FLEXISOFT EIP GATEW. with serial number <=2311xxxx with Firmware <=V2.11.0, SICK FX0-GMOD00000 FLEXISOFT MOD GATEW. with serial number <=2311xxxx with Firmware <=V2.11.0, SICK FX0-GPNT00000 FLEXISOFT PNET GATEW. with serial number <=2311xxxx with Firmware <=V2.12.0, SICK FX0-GENT00030 FLEXISOFT EIP GATEW.V2 with serial number <=2311xxxx all Firmware versions, SICK FX0-GPNT00030 FLEXISOFT PNET GATEW.V2 with serial number <=2311xxxx all Firmware versions and SICK FX0-GMOD00010 FLEXISOFT MOD GW with serial number <=2311xxxx with Firmware <=V2.11.0 all have Telnet enabled by factory default. No password is set in the default configuration.

Why

The code uses deprecated or obsolete functions, which suggests that the code has not been actively reviewed or maintained.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

The Flexi Classic and Flexi Soft Gateways SICK UE410-EN3 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK UE410-EN1 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK UE410-EN3S04 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK UE410-EN4 FLEXI ETHERNET GATEW. with serial number <=2311xxxx all Firmware versions, SICK FX0-GENT00000 FLEXISOFT EIP GATEW. with serial number <=2311xxxx with Firmware <=V2.11.0, SICK FX0-GMOD00000 FLEXISOFT MOD GATEW. with serial number <=2311xxxx with Firmware <=V2.11.0, SICK FX0-GPNT00000 FLEXISOFT PNET GATEW. with serial number <=2311xxxx with Firmware <=V2.12.0, SICK FX0-GENT00030 FLEXISOFT EIP GATEW.V2 with serial number <=2311xxxx all Firmware versions, SICK FX0-GPNT00030 FLEXISOFT PNET GATEW.V2 with serial number <=2311xxxx all Firmware versions and SICK FX0-GMOD00010 FLEXISOFT MOD GW with serial number <=2311xxxx with Firmware <=V2.11.0 all have Telnet enabled by factory default. No password is set in the default configuration.

Why

The code uses deprecated or obsolete functions, which suggests that the code has not been actively reviewed or maintained.

How

An attacker operating through a network path may attempt exploitation without authentication or 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
a network path → Use of Obsolete Function → cause the confidentiality, integrity or availability impact described by the vendor
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-477 ↗

CWE-477: Use of Obsolete Function. The code uses deprecated or obsolete functions, which suggests that the code has not been actively reviewed or maintained.

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: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.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.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
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.
NetworkUnauthenticatedCWE-477
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-20230426Security Bulletin 26 Apr 2023

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 26 Apr 2023, published on 26 April 2023. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2023-009415複数の Sick 製品における重要な機能に対する認証の欠如に関する脆弱性

ue410-en3 ファームウェア、ue410-en1 ファームウェア、ue410-en3s04 ファームウェア等複数の Sick 製品には、重要な機能に対する認証の欠如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
SICK recommends to set a strong password for the Telnet protocol once the Gateway is put into operation. It is possible to set a password with a maximum length of 15 characters. Enter the following commands to change the Telnet password: ```bash $ telnet Password: [Enter] passwd quit [Enter] $ telnet Password: [Enter] ``` Test if [Enter] still works and if the new password is saved.
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 19 Apr 2023 · Last source change 5 Feb 2025, 15:24 UTC · CWE-477 · Use of Obsolete Function

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-2023-27551
Product sourceVendor CSAF · SICK PSIRT
Remediation sourceVendor CSAF · SICK PSIRT
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
    <=2311xxxx; <=V2.11.0 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    <=2311xxxx; <=V2.11.0 · Fixed: SICK recommends to set a strong password for the Telnet protocol once the Gateway is put into operation. It is possible to set a password with a maximum length of 15 characters. Enter the following commands to change the Telnet password: ```bash $ telnet Password: [Enter] passwd quit [Enter] $ telnet Password: [Enter] ``` Test if [Enter] still works and if the new password is saved.
    SICK PSIRT ↗
  2. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    SICK PSIRT ↗
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-2023-27551↗SICK PSIRT 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-2023-23451 · cve.blacktree.nl