Cyber Resilience

CVE-2021-34583

HighPublic PoC

Published: 26 October 2021

Published
26 October 2021
Modified
15 August 2025
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0069 72.3th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-34583 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Wago 750-8214 Firmware. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 27.7% 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 may cause a heap-based buffer overflow and could therefore trigger a denial-of- service condition due to a crash in the CODESYS V2 web server prior to V1.1.9.22.

CWE(s)

Related Threats

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

Affected Assets

wago
750-8214 firmware
≤ fw20
wago
750-8216 firmware
≤ fw20
wago
750-8217 firmware
≤ fw20
wago
750-8213 firmware
≤ fw20
wago
750-8212 firmware
≤ fw20
wago
750-8211 firmware
≤ fw20
wago
750-8210 firmware
≤ fw20
wago
750-8208 firmware
≤ fw20
wago
750-8207 firmware
≤ fw20
wago
750-8206 firmware
≤ fw20
+18 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References