Cyber Resilience

CVE-2021-34595

High

Published: 26 October 2021

Published
26 October 2021
Modified
15 August 2025
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
EPSS Score 0.0037 59.4th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-34595 is a high-severity Use of Out-of-range Pointer Offset (CWE-823) vulnerability in Wago 750-823 Firmware. Its CVSS base score is 8.1 (High).

Operationally, ranked in the top 40.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A crafted request with invalid offsets may cause an out-of-bounds read or write access in CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56, resulting in a denial-of-service condition or local memory overwrite.

CWE(s)

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
+20 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-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

References