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Vulnerability record · CVE-2021-34581 · published 31 August 2021

CVE-2021-34581: Wago 750-880\/040-000 firmware vulnerability

Wago · 750 880\/040 000 Firmware

Missing Release of Resource after Effective Lifetime vulnerability in OpenSSL implementation of WAGO 750-831/xxx-xxx, 750-880/xxx-xxx, 750-881, 750-889 in versions FW4 up to FW15 allows an unauthenticated attacker to cause DoS on the device.

7.5 CVSS 3.1 High EPSS 1.0% · top 37.1% CWE-772 · CWE-772
7.5CVSS 3.1 base score, v2 7.8
1.0%EPSS exploitation probability, 30 days
NoNot in CISA KEV
9Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

Missing Release of Resource after Effective Lifetime vulnerability in OpenSSL implementation of WAGO 750-831/xxx-xxx, 750-880/xxx-xxx, 750-881, 750-889 in versions FW4 up to FW15 allows an unauthenticated attacker to cause DoS on the device.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

9 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://cert.vde.com/en-us/advisories/vde-2021-038 Third Party Advisory
https://cert.vde.com/en-us/advisories/vde-2021-038 Third Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2021-30190Wago 750-893 firmware missing authentication for critical function vulnerabilityCODESYS V2 Web-Server before 1.1.9.20 has Improper Access Control.EPSS 1.4%9.8CVE-2021-30188Wago 750-893 firmware out-of-bounds write vulnerabilityCODESYS V2 runtime system SP before 2.4.7.55 has a Stack-based Buffer Overflow.EPSS 1.3%9.8CVE-2021-30193Wago 750-893 firmware out-of-bounds write vulnerabilityCODESYS V2 Web-Server before 1.1.9.20 has an Out-of-bounds Write.EPSS 1.1%9.8CVE-2021-30189Wago 750-893 firmware out-of-bounds write vulnerabilityCODESYS V2 Web-Server before 1.1.9.20 has a Stack-based Buffer Overflow.EPSS 1.2%9.8CVE-2021-30192Wago 750-893 firmware vulnerabilityCODESYS V2 Web-Server before 1.1.9.20 has an Improperly Implemented Security Check.EPSS 1.1%9.8CVE-2019-10712Wago 750-830 firmware hard-coded credentials vulnerabilityThe Web-GUI on WAGO Series 750-88x (750-330, 750-352, 750-829, 750-831, 750-852, 750-880, 750-881, 750-882, 750-884, 750-885, 750-889) and Series 750…EPSS 2.8%9.1CVE-2021-34584Wago 750-823 firmware vulnerabilityCrafted web server requests can be utilised to read partial stack or heap memory or may trigger a denial-of- service condition due to a crash in the …EPSS 1.1%9.1CVE-2021-30194Wago 750-893 firmware out-of-bounds read vulnerabilityCODESYS V2 Web-Server before 1.1.9.20 has an Out-of-bounds Read.EPSS 1.1%

Source: NIST National Vulnerability Database (record CVE-2021-34581), CISA KEV, FIRST EPSS (scores of 2026-10-19). This page is refreshed as NVD updates the record.