CVE-2021-33834
CVE-2021-33834 is a high-severity vulnerability in Insyde H2offt with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.
Key facts
- Severity: High (CVSS 3.x base score 7.1)
- EPSS exploit prediction: 0% (8th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-787
- Affected product: Insyde H2offt
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2021-33834?
- 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.
- How severe is CVE-2021-33834?
- CVE-2021-33834 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
- Is CVE-2021-33834 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-33834?
- CVE-2021-33834 primarily affects Insyde H2offt. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-33834?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-33834 published?
- CVE-2021-33834 was published on 2023-09-08 and last updated on 2026-06-17.
References
Affected products (2)
- cpe:2.3:a:insyde:h2offt:6.20.00:*:*:*:*:*:*:*
- cpe:2.3:a:insyde:iscflashx64.sys:3.9.3.0:*:*:*:*:*:*:*
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