CVE-2021-34567

highpriority · track · 0EPSS 0.009 · 58 %ileDEEUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.86% (58th) EPSS
CVSS 8.2 · high
Is it mine?
112 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · nvd · wago_psirt

EPSS · scored 2026-10-27

In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a specially crafted packet containing OS commands to provoke a denial of service and an limited out-of-bounds read.

01

remediations

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

A vendor fix is available.

  • Fixedwago_psirt

    The I/O-Check service protocol is only needed during installation and commissioning, not during normal operations. It is highly recommended to disable the I/O-Check service after commissioning. This is the easiest and securest way to protect your device from the listed vulnerabilities and possible upcoming zero-day exploits. Regardless to the action described above, the vulnerability has been fixed in FW18Patch3, released in June 2021. We recommend all affected users to update to the latest firmware version.

  • Mitigationwago_psirt

    - Disable I/O-Check service - Restrict network access to the device. - Do not directly connect the device to the internet.

02

cvss

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

8.2
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.18.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Hsecondary · ENISA EU
v3.18.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Hsecondary · info@cert.vde.comexploitability 3.9 · impact 4.2
v3.18.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Hsecondary · WAGO PSIRT DE
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-125USCWE-125US
05

affected products (112)

Products and version ranges known to be affected.

showing 20 of 112
06

advisories (1)

Vendor and ecosystem advisories describing this.

  • VDE-2020-036WAGO: Multiple Vulnerabilities in I/O-Check Service2021-06-29csaf · wago_psirtDE

    Multiple vulnerabilities in the WAGO I/O-Check Service were reported.

07

also known as (3)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdnvdwago_psirtNVDCVE.orgMITRE
published 2022-11-09modified 2026-06-17
09

references (4)

External citations — patches, advisories, analysis.

scry

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