CVE-2021-43323 Privilege escalation in n/a

High 8.2 Published 3 Feb 2022 Updated 11 Aug 2026

An SMM callout vulnerability in InsydeH2O firmware allows attackers to hijack execution flow and escalate privileges to System Management Mode.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-43323?

CVE-2021-43323 is a high-severity vulnerability in Insyde Insydeh2o, published on 3 Feb 2022. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

An issue was discovered in UsbCoreDxe in Insyde InsydeH2O with kernel 5.5 before 05.51.45, 5.4 before 05.43.45, 5.3 before 05.35.45, 5.2 before 05.26.45, 5.1 before 05.16.45, and 5.0 before 05.08.45. An SMM callout vulnerability allows an attacker to hijack execution flow of code running in System Management Mode. Exploiting this issue could lead to escalating privileges to SMM.

Which versions are affected by CVE-2021-43323?

It affects 1 product.

Products include Insyde Insydeh2o.

How do I fix CVE-2021-43323?

No fix has been published for CVE-2021-43323 yet. Limit exposure of the affected software until one is available.

Is CVE-2021-43323 being exploited?

There is no known exploitation of CVE-2021-43323 in the wild and no public exploit code.

All Insyde Insydeh2o vulnerabilities

Sources

Also known as GHSA-v6h3-3hh9-32cf.