Cyber Resilience

CVE-2021-34584

CriticalPublic PoC

Published: 26 October 2021

Published
26 October 2021
Modified
15 August 2025
KEV Added
—
Patch
—
CVSS Score v3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS Score 0.0061 70.2th percentile
Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-34584 is a critical-severity Buffer Over-read (CWE-126) vulnerability in Wago 750-823 Firmware. Its CVSS base score is 9.1 (Critical).

Operationally, ranked in the top 29.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Crafted 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 CODESYS V2 web server prior to V1.1.9.22.

CWE(s)
CWE-126

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

wago
750-823 firmware
≤ fw10
wago
750-829 firmware
≤ fw17
wago
750-831 firmware
≤ fw17
wago
750-832 firmware
≤ fw10
wago
750-852 firmware
≤ fw17
wago
750-862 firmware
≤ fw10
wago
750-880 firmware
≤ fw17
wago
750-881 firmware
≤ fw17
wago
750-882 firmware
≤ fw17
wago
750-885 firmware
≤ fw17
+18 more product configuration(s) — see NVD for full list

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References