How severe is CVE-2021-38578?

CVE-2021-38578 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2021-38578 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-38578?

CVE-2021-38578 primarily affects Tianocore Edk2. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-38578?

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-2021-38578 published?

CVE-2021-38578 was published on 2022-03-03 and last updated on 2026-06-17.

CVE-2021-38578

CVE-2021-38578 is a high-severity vulnerability in Tianocore Edk2 with a CVSS 3.x base score of 7.4. 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 7.4)
CVSS v2: 7.5
EPSS exploit prediction: 1% (58th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Tianocore Edk2
Published: 2022-03-03
Last modified: 2026-06-17

Description

Existing CommBuffer checks in SmmEntryPoint will not catch underflow when computing BufferSize.

Frequently asked questions

What is CVE-2021-38578?: Existing CommBuffer checks in SmmEntryPoint will not catch underflow when computing BufferSize.
How severe is CVE-2021-38578?: CVE-2021-38578 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2021-38578 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-38578?: CVE-2021-38578 primarily affects Tianocore Edk2. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-38578?: 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-2021-38578 published?: CVE-2021-38578 was published on 2022-03-03 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:a:tianocore:edk2:*:*:*:*:*:*:*:*
cpe:2.3:o:insyde:kernel:5.0:*:*:*:*:*:*:*
cpe:2.3:o:insyde:kernel:5.1:*:*:*:*:*:*:*
cpe:2.3:o:insyde:kernel:5.2:*:*:*:*:*:*:*
cpe:2.3:o:insyde:kernel:5.3:*:*:*:*:*:*:*
cpe:2.3:o:insyde:kernel:5.4:*:*:*:*:*:*:*
cpe:2.3:o:insyde:kernel:5.5:*:*:*:*:*:*:*

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