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Fencer Intel
high 7.5

CVE-2021-27432 json

OPC Foundation UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy are vulnerable to an uncontrolled recursion, which may…

published 5y ago modified 4mo ago also EUVD-2021-14186

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.0%
EPSS 2.0% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

OPC Foundation UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy are vulnerable to an uncontrolled recursion, which may allow an attacker to trigger a stack overflow.

Patch / fix

  • opcfoundation ua_.net_standard_stack 1.4.365.48

Is CVE-2021-27432 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-294-03 updated cvss 7.5

ICONICS GENESIS64 and Mitsubishi Electric MC Works64 OPC UA

  • ICONICS, Mitsubishi Electric AnalytiX <= 10.97 ICONICS, Mitsubishi Electric GENESIS64 <= 10.97 ICONICS, Mitsubishi Electric Hyper Historian <= 10.97 ICONICS, Mitsubishi Electric MC Works64 <= 4.04E ICONICS, Mitsubishi Electric MobileHMI <= 10.97
    affected: mitigation “Place control system networks and devices behind firewalls to isolate them from the business network.” mitsubishielectric.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

cisa ICSA-21-133-03 updated cvss 7.5

OPC Foundation UA Products Built with .NET Framework

  • OPC Foundation OPC UA .NET Standard < 1.4.365.48
    affected: vendor fix github.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

1.95% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • n/a OPC Foundation OPC UA .NET Standard and OPC UA .NET Legacy

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.