NVD / CVE Program· CNA CERTVDE

CVE-2021-34578: WAGO: Authentication Vulnerability in Web-Based Management

Noroxi assessment

Priority: Monitor (action score 32/100)

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: 0.96% (FIRST EPSS); higher than 61.9% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
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

This vulnerability allows an attacker who has access to the WBM to read and write settings-parameters of the device by sending specifically constructed requests without authentication on multiple WAGO PLCs in firmware versions up to FW07.

HighCVSS 8.1 · v3.1—No exploit No fix recorded

Published: Aug 31, 2021
Updated: Jun 16, 2026
EPSS: 0.9% · 61th percentile
CWE: CWE-287

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 32 / 40 · 8.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.9%

CNA vs NVD score

NVD: 8.1
CNA · CERTVDE: 9.8; 1.7 point gap

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

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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.

Vendor	Product	CPE
wago	750-890\/040-000 firmware	cpe:2.3:o:wago:750-890\/040-000_firmware
wago	750-890\/040-000	cpe:2.3:h:wago:750-890\/040-000
wago	750-890\/025-001 firmware	cpe:2.3:o:wago:750-890\/025-001_firmware
wago	750-890\/025-001	cpe:2.3:h:wago:750-890\/025-001
wago	750-890\/025-002 firmware	cpe:2.3:o:wago:750-890\/025-002_firmware
wago	750-890\/025-002	cpe:2.3:h:wago:750-890\/025-002
wago	750-890\/025-000 firmware	cpe:2.3:o:wago:750-890\/025-000_firmware
wago	750-890\/025-000	cpe:2.3:h:wago:750-890\/025-000
wago	750-832\/000-002 firmware	cpe:2.3:o:wago:750-832\/000-002_firmware
wago	750-832\/000-002	cpe:2.3:h:wago:750-832\/000-002
wago	750-362 firmware	cpe:2.3:o:wago:750-362_firmware
wago	750-362	cpe:2.3:h:wago:750-362

and 12 more

Affected versions

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

wago 750-362 firmwareup to fw07 inclusive
wago 750-363 firmwareup to fw07 inclusive
wago 750-823 firmwareup to fw07 inclusive
wago 750-832 firmwareup to fw07 inclusive
wago 750-832/000-002 firmwareup to fw07 inclusive
wago 750-862 firmwareup to fw07 inclusive
wago 750-890/025-000 firmwareup to fw07 inclusive
wago 750-890/025-001 firmwareup to fw07 inclusive
wago 750-890/025-002 firmwareup to fw07 inclusive
wago 750-890/040-000 firmwareup to fw07 inclusive
wago 750-891 firmwareup to fw07 inclusive
wago 750-893 firmwareup to fw07 inclusive

Versions reported by the vendor

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

WAGO PLC
- 750-362 and later · up to and including FW07affected
- 750-363 and later · up to and including FW07affected
- 750-823 and later · up to and including FW07affected
- 750-832/xxx-xxx and later · up to and including FW07affected
- 750-862 and later · up to and including FW07affected
- 750-891 and later · up to and including FW07affected
- 750-890/xxx-xxx and later · up to and including FW07affected
- 750-893 and later · up to and including FW07affected

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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Maxim Rupp (https://rupp.it) reported this vulnerability to WAGO. CERT@VDE coordinated.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
Special conditions such as timing or configuration are required.

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: Network
Attack complexity: High
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:N/AC:H/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

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

References

cert.vde.com/en-us/advisories/vde-2020-044

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

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