CVE-2021-34578

mediumpriority · track · 32EPSS 0.010 · 62 %ileDEEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.96% (62nd) EPSS
CVSS 6.8 · medium
Is it mine?
36 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · nvd · wago_psirt

EPSS · scored 2026-10-28

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.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

  • Fixedwago_psirt

    Update the device to the latest FW version.

  • Mitigationwago_psirt

    * Restrict network access to the device. * Do not directly connect the device to the internet. * Disable unused TCP/UDP ports. * Disable web-based management ports 80/443 after the configuration phase

02

cvss

Technical severity, 0–10. One row per scoring source.

9.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 6.8–9.8

v2.06.8mediumAV:N/AC:M/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 6.4
v3.18.1highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.2 · impact 5.9
v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU
v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · info@cert.vde.comexploitability 3.9 · impact 5.9
v3.18.1highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · WAGO PSIRT DE
v3.17.4highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-287USCWE-287US
04

affected products (36)

Products and version ranges known to be affected.

showing 20 of 36
05

advisories (1)

Vendor and ecosystem advisories describing this.

  • VDE-2020-044WAGO: Web-Based Management Authentication Vulnerability in WAGO 750-36X and WAGO 750-8XX2021-08-31csaf · wago_psirtDE

    The Web-Based Management (WBM) of WAGOs programmable logic controller (PLC) is typically used for administration, commissioning and updates. With special crafted requests it is possible to read and write some special parameters without authentication. This vulnerability is different to advisory SAV-2020-014 / VDE-2020-028

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdnvdwago_psirtNVDCVE.orgMITRE
published 2021-08-31modified 2026-06-17
08

references (4)

External citations — patches, advisories, analysis.

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