CVE Vulnerabilities

CVE-2021-38578

Buffer Underwrite ('Buffer Underflow')

Published: Mar 03, 2022 | Modified: Nov 03, 2025
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
7.4 MODERATE
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
Ubuntu
MEDIUM
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Existing CommBuffer checks in SmmEntryPoint will not catch underflow when computing BufferSize.

Weakness

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

Affected Software

NameVendorStart VersionEnd Version
Edk2Tianocore*202202 (including)
Red Hat Enterprise Linux 9RedHatedk2-0:20221207gitfff6d81270b5-9.el9_2*
Edk2Ubuntubionic*
Edk2Ubuntuesm-apps/bionic*
Edk2Ubuntuesm-apps/xenial*
Edk2Ubuntuesm-infra/focal*
Edk2Ubuntufocal*
Edk2Ubuntuimpish*
Edk2Ubuntujammy*
Edk2Ubuntukinetic*
Edk2Ubuntutrusty*
Edk2Ubuntuxenial*

Potential Mitigations

References