NVD / CVE Program· CNA schneider

CVE-2023-25556: A CWE-287: Improper Authentication vulnerability exists that could allow a device to be compromised when a key of less than seven digits is…

HighCVSS 8.8 · v3.1—No exploit No fix recorded

Noroxi assessment

Priority: Monitor (action score 35/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.35% (FIRST EPSS).
Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A CWE-287: Improper Authentication vulnerability exists that could allow a device to be compromised when a key of less than seven digits is entered and the attacker has access to the KNX installation.

BDU:2023-01595

Published: Apr 18, 2023
Updated: Jun 17, 2026
EPSS: 0.3% · 29th percentile
CWE: CWE-287

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.3%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 8.8
CNA · schneider: 8.3; 0.5 point gap

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

ProductVersion

Vendor	Product	CPE
schneider-electric	merten instabus tastermodul 1fach system m firmware	cpe:2.3:o:schneider-electric:merten_instabus_tastermodul_1fach_system_m_firmware
schneider-electric	merten instabus tastermodul 1fach system m	cpe:2.3:h:schneider-electric:merten_instabus_tastermodul_1fach_system_m
schneider-electric	merten instabus tastermodul 2fach system m firmware	cpe:2.3:o:schneider-electric:merten_instabus_tastermodul_2fach_system_m_firmware
schneider-electric	merten instabus tastermodul 2fach system m	cpe:2.3:h:schneider-electric:merten_instabus_tastermodul_2fach_system_m
schneider-electric	merten tasterschnittstelle 4fach plus firmware	cpe:2.3:o:schneider-electric:merten_tasterschnittstelle_4fach_plus_firmware
schneider-electric	merten tasterschnittstelle 4fach plus	cpe:2.3:h:schneider-electric:merten_tasterschnittstelle_4fach_plus
schneider-electric	merten knx argus 180\/2\,20m up system firmware	cpe:2.3:o:schneider-electric:merten_knx_argus_180\/2\,20m_up_system_firmware
schneider-electric	merten knx argus 180\/2\,20m up system	cpe:2.3:h:schneider-electric:merten_knx_argus_180\/2\,20m_up_system
schneider-electric	merten jalousie-\/schaltaktor reg-k\/8x\/16x\/10 m. hb firmware	cpe:2.3:o:schneider-electric:merten_jalousie-\/schaltaktor_reg-k\/8x\/16x\/10_m._hb_firmware
schneider-electric	merten jalousie-\/schaltaktor reg-k\/8x\/16x\/10 m. hb	cpe:2.3:h:schneider-electric:merten_jalousie-\/schaltaktor_reg-k\/8x\/16x\/10_m._hb
schneider-electric	merten knx uni-dimmaktor ll reg-k\/2x230\/300 w firmware	cpe:2.3:o:schneider-electric:merten_knx_uni-dimmaktor_ll_reg-k\/2x230\/300_w_firmware
schneider-electric	merten knx uni-dimmaktor ll reg-k\/2x230\/300 w	cpe:2.3:h:schneider-electric:merten_knx_uni-dimmaktor_ll_reg-k\/2x230\/300_w

and 2 more

Versions reported by the vendor

Affected version ranges reported by the assigning authority (schneider). Independent of NVD's CPE analysis and usually ahead of it.

Schneider Electric Merten INSTABUS Tastermodul 1fach System M 625199
- Program Version 1.0affected
Schneider Electric Merten INSTABUS Tastermodul 2fach System M 625299
- Program Version 1.0affected
Schneider Electric Merten Jalousie-/Schaltaktor REG-K/8x/16x/10 m. HB 649908
- Program Version 1.0affected
Schneider Electric Merten KNX ARGUS 180/2,20M UP SYSTEM 631725
- Program Version 1.0affected
Schneider Electric Merten KNX Schaltakt.2x6A UP m.2 Eing. MEG6003-0002
- Program Version 0.1affected
Schneider Electric Merten KNX Uni-Dimmaktor LL REG-K/2x230/300 W MEG6710-0002
- Program Version 1.0, Program Version 1.1affected
Schneider Electric Merten Tasterschnittstelle 4fach plus 670804
- Program Version 1.0, Program Version 1.2affected

Affected versions · NVD (9)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

schneider-electric merten instabus tastermodul 1fach system m firmware1.0
schneider-electric merten instabus tastermodul 2fach system m firmware1.0
schneider-electric merten jalousie-/schaltaktor reg-k/8x/16x/10 m. hb firmware1.0
schneider-electric merten knx argus 180/2,20m up system firmware1.0
schneider-electric merten knx schaltakt.2x6a up m.2 eing. firmware0.1
schneider-electric merten knx uni-dimmaktor ll reg-k/2x230/300 w firmware1.0
schneider-electric merten knx uni-dimmaktor ll reg-k/2x230/300 w firmware1.1
schneider-electric merten tasterschnittstelle 4fach plus firmware1.0
schneider-electric merten tasterschnittstelle 4fach plus firmware1.2

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

Someone on the same network segment can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Adjacent
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-287 · Improper Authentication

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

Authentication is added route by route instead of being enforced in one place. When a route added later bypasses the shared middleware, the session check never runs for it.

The bug in code

The whole CWE-287 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1app.use("/admin", requireSession, adminRouter);
2

3// Route added later skips the middleware
4app.post("/admin-api/config", updateConfig);

Fixed

1const admin = express.Router();
2admin.use(requireSession, requireRole("admin"));
3

4admin.post("/config", updateConfig);
5app.use("/admin", admin);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Change log (0)

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

download.schneider-electric.com/files?p_Doc_Ref=SEVD-2023-045-03&p_enDocType=Security+and+Safety+Notice&p_File_Name=SEVD-2023-045-03.pdf

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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