CVE-2021-34568Network attack vector

Unauthenticated denial of service via resource exhaustion

Published Nov 9, 2022 · Updated May 1, 2025

Resource exhaustion in WAGO I/O-Check Service through FW18 Patch 2 allows remote attackers to interrupt affected controllers and panels. The service accepts specially crafted network packets containing OS commands and allocates resources without limits or throttling until service availability is lost. No authentication or user interaction is required, and the published record reports denial of service without confidentiality or integrity impact.

CVSS severity7.5
High
EPSS probability1.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Resource exhaustion in WAGO I/O-Check Service through FW18 Patch 2 allows remote attackers to interrupt affected controllers and panels. The service accepts specially crafted network packets containing OS commands and allocates resources without limits or throttling until service availability is lost. No authentication or user interaction is required, and the published record reports denial of service without confidentiality or integrity impact.

The record

CVE
CVE-2021-34568
Published
Nov 9, 2022
Updated
May 1, 2025
Vendor
WAGO
Product
Edge Controller 0752-8303/8000-0002
Classifications
CWE-770, CAPEC-130, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 9, 2022CVE publishedPublication date reported by the CVE source.
  2. May 1, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=FW1 <=FW18 Patch 2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WAGO · Edge Controller 0752-8303/8000-0002version=FW1 <=FW18 Patch 2
WAGO · PFC200 Controllerversion=FW1 <=FW18 Patch 2
WAGO · Touch Panel 600 Advanced Lineversion=FW1 <=FW18 Patch 2
WAGO · Touch Panel 600 Marine Lineversion=FW1 <=FW18 Patch 2
WAGO · Touch Panel 600 Standard Lineversion=FW1 <=FW18 Patch 2
WAGO · PFC100 Controllerversion=FW1 <=FW18 Patch 2

Published CVSS scores

7.5CERT@VDECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
CAPEC-130Excessive Allocation
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo