How severe is CVE-2021-34567?

CVE-2021-34567 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability high.

Is CVE-2021-34567 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34567?

CVE-2021-34567 primarily affects Wago 750-8100 Firmware. In total, 196 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-34567?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-34567 published?

CVE-2021-34567 was published on 2022-11-09 and last updated on 2026-06-17.

CVE-2021-34567

CVE-2021-34567 is a high-severity vulnerability in Wago 750-8100 Firmware with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: High (CVSS 3.x base score 8.2)
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Wago 750-8100 Firmware
Published: 2022-11-09
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-34567?: 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.
How severe is CVE-2021-34567?: CVE-2021-34567 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability high.
Is CVE-2021-34567 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34567?: CVE-2021-34567 primarily affects Wago 750-8100 Firmware. In total, 196 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-34567?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-34567 published?: CVE-2021-34567 was published on 2022-11-09 and last updated on 2026-06-17.

References

https://cert.vde.com/en/advisories/VDE-2020-036/

Affected products (196)

cpe:2.3:o:wago:750-8100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8100_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8100_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8100_firmware:18:patch_2:*:*:*:*:*:*
cpe:2.3:o:wago:750-8101_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8101_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8101_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8101_firmware:18:patch_2:*:*:*:*:*:*
cpe:2.3:o:wago:750-8101\/025-000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8101\/025-000_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8101\/025-000_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8101\/025-000_firmware:18:patch_2:*:*:*:*:*:*
cpe:2.3:o:wago:750-8102_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8102_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8102_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8102_firmware:18:patch_2:*:*:*:*:*:*
cpe:2.3:o:wago:750-8102\/025-000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8102\/025-000_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8102\/025-000_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8102\/025-000_firmware:18:patch_2:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202_firmware:18:patch_2:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-011_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-011_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-011_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-011_firmware:18:patch_2:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-012_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-012_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-012_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-012_firmware:18:patch_2:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-022_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-022_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-022_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/000-022_firmware:18:patch_2:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/025-000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/025-000_firmware:18:-:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/025-000_firmware:18:patch_1:*:*:*:*:*:*
cpe:2.3:o:wago:750-8202\/025-000_firmware:18:patch_2:*:*:*:*:*:*

More vulnerabilities in Wago 750-8100 Firmware

CVE-2021-34569 — Critical (CVSS 9.8): In WAGO I/O-Check Service in multiple products an attacker can send a specially crafted packet containing OS commands…
CVE-2021-34566 — Critical (CVSS 9.1): In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a specially crafted packet…
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CVE-2021-34568 — High (CVSS 7.5): In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a specially crafted packet…
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CVE-2022-22511 — Medium (CVSS 5.4): Various configuration pages of the device are vulnerable to reflected XSS (Cross-Site Scripting) attacks. An authorized…

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Other CWE-125 (Out-of-bounds Read) vulnerabilities

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CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

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