Is CVE-2021-33834 actively exploited?

No active exploitation of CVE-2021-33834 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-33834 be exploited remotely?

No. CVE-2021-33834 requires local access to exploit.

What is the CVSS score of CVE-2021-33834?

CVE-2021-33834 has a CVSS score of 7.1 (HIGH).

HOME VULNERABILITIESCVE-2021-33834

HIGH

CVE-2021-33834

CWE-787Published: September 8, 2023· Updated: Jun 17, 2026

7.1

CVSS v3.1

Official Description

An issue was discovered in iscflashx64.sys 3.9.3.0 in Insyde H2OFFT 6.20.00. When handling IOCTL 0x22229a, the input used to allocate a buffer and copy memory is mishandled. This could cause memory corruption or a system crash.

NVD Source

Technical Analysis

CVE-2021-33834 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), availability disruption (denial of service), with a CVSS base score of 7.1.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.