CVE-2021-38578

Advisory lineage Upstream: 0 Downstream: 12
Modified
Published: 03 Mar 2022, 21:53
Last modified:03 Nov 2025, 19:26

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (nvd)
EPSS Score
0.06% LOW
0% probability -0.01%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

03 Mar 2022, 21:53
Published
Vulnerability first disclosed
03 Nov 2025, 19:26
Last Modified
Vulnerability information updated

Description

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

CVSS Metrics

  • v3.1•HIGH•Score: 7.4CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
  • v2.0•HIGH•Score: 7.5AV:N/AC:L/Au:N/C:P/I:P/A:P

EPSS Trends

Current EPSS score: 0.06%• Percentile: 20%

Techniques & Countermeasures

  • CWE-124•Buffer Underwrite ('Buffer Underflow')

    The product writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer.

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • insyde•kernel

    5.0 | 5.1 | 5.2 | 5.3 | 5.4 | 5.5

  • tianocore•edk ii

    edk2-stable202208

  • tianocore•edk2

    ≤ 202202

References (3)