CVE-2021-27432 Denial of service in OPC Foundation OPC UA .NET Standard and OPC UA .NET Legacy

High 7.5 Published 20 May 2021 Updated 3 Aug 2024

An attacker can trigger a stack overflow via uncontrolled recursion in the OPC UA .NET library, causing a denial of service.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-27432?

CVE-2021-27432 is a high-severity denial of service vulnerability in OPC Foundation OPC UA .NET Standard and OPC UA .NET Legacy, published on 20 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-674

Which versions are affected by CVE-2021-27432?

It affects 2 products.

Products include Opcfoundation Ua-.Net-Legacy, Opcfoundation Ua .Net Standard Stack.

How do I fix CVE-2021-27432?

No fix has been published for CVE-2021-27432 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-27432 being exploited?

There is no known exploitation of CVE-2021-27432 in the wild and no public exploit code.

Sources

Also known as GHSA-5rm8-9376-7gg5.