CVE-2023-40548 HIGH

CVE-2023-40548: Shim: interger overflow leads to heap buffer overflow in verify_sbat_section on 32-bits systems

Weakness CWE-190
Published January 29, 2024
Last update June 26, 2026
View on NVD All CVEs

CVSS base score

7.4/10
Attack vector Local
Attack complexity High
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

A buffer overflow was found in Shim in the 32-bit system. The overflow happens due to an addition operation involving a user-controlled value parsed from the PE binary being used by Shim. This value is further used for memory allocation operations, leading to a heap-based buffer overflow. This flaw causes memory corruption and can lead to a crash or data integrity issues during the boot phase.

Key dates

02Disclosure timeline

January 29, 2024 CVE published
June 26, 2026 Record updated