CVE-2021-34566
WAGO I/O-Check Service prone to Memory Overflow
In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a specially crafted packet containing OS commands to crash the iocheck process and write memory resulting in loss of integrity and DoS.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
WAGO I/O-Check Service prone to Memory Overflow
In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a specially crafted packet containing OS commands to crash the iocheck process and write memory resulting in loss of integrity and DoS.
- Record
CVE-2021-34566- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
EUVDEUVD-2021-21216
In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a specially crafted packet containing OS commands to crash the iocheck process and write memory resulting in loss of integrity and DoS.
- Record
EUVD-2021-21216- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-xcqq-8632-69xx
In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a...
In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a specially crafted packet containing OS commands to crash the iocheck process and write memory resulting in loss of integrity and DoS.
- Record
GHSA-xcqq-8632-69xx- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
NVD
In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a specially crafted packet containing OS commands to crash the iocheck process and write memory resulting in loss of integrity and DoS.
- Record
CVE-2021-34566- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
Affected products
- wago 750-8100 firmware
- wago 750-8101\/025-000 firmware
- wago 750-8101 firmware
- wago 750-8102\/025-000 firmware
- wago 750-8102 firmware
- wago 750-81xx/xxx-xxxfw
- wago 750-8202\/000-011 firmware
- wago 750-8202\/000-012 firmware
- wago 750-8202\/000-022 firmware
- wago 750-8202\/025-000 firmware
- wago 750-8202\/025-001 firmware
- wago 750-8202\/025-002 firmware
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- wago 750-8202\/040-000 firmware
- wago 750-8202\/040-001 firmware
- wago 750-8202 firmware
- wago 750-82xx/xxx-xxx
- wago 752-8303/8000-0002
- wago 752-8303\/8000-002 firmware
- wago 762-4101 firmware
- wago 762-4102 firmware
- wago 762-4103 firmware
- wago 762-4104 firmware
- wago 762-4201\/8000-001 firmware
- wago 762-4202\/8000-001 firmware
- wago 762-4203\/8000-001 firmware
- wago 762-4204\/8000-001 firmware
- wago 762-4205\/8000-001 firmware
- wago 762-4205\/8000-002 firmware
- wago 762-4206\/8000-001 firmware
- wago 762-4206\/8000-002 firmware
- wago 762-4301\/8000-002 firmware
- wago 762-4302\/8000-002 firmware
- wago 762-4303\/8000-002 firmware
- wago 762-4304\/8000-002 firmware
- wago 762-4305\/8000-002 firmware
- wago 762-4306\/8000-002 firmware
- wago 762-4xxx
- wago 762-5203\/8000-001 firmware
- wago 762-5204\/8000-001 firmware
- wago 762-5205\/8000-001 firmware
- wago 762-5206\/8000-001 firmware
- wago 762-5303\/8000-002 firmware
- wago 762-5304\/8000-002 firmware
- wago 762-5305\/8000-002 firmware
- wago 762-5306\/8000-002 firmware
- wago 762-5xxx
- wago 762-6201\/8000-001 firmware
- wago 762-6202\/8000-001 firmware
- wago 762-6203\/8000-001 firmware
- wago 762-6204\/8000-001 firmware
- wago 762-6301\/8000-002 firmware
- wago 762-6302\/8000-002 firmware
- wago 762-6303\/8000-002 firmware
- wago 762-6304\/8000-002 firmware
- wago 762-6xxx
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-34566 is a critical vulnerability (CVSS 9.1) in Wago 750-8100 Firmware, published November 9, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.35%, the 71st percentile. No source names a fixed version.