CVE-2023-40547
CVE-2023-40547CVE-2023-40547
redhat / shim
Description
A remote code execution vulnerability was found in Shim. The Shim boot support trusts attacker-controlled values when parsing an HTTP response. This flaw allows an attacker to craft a specific malicious HTTP request, leading to a completely controlled out-of-bounds write primitive and complete system compromise. This flaw is only exploitable during the early boot phase, an attacker needs to perform a Man-in-the-Middle or compromise the boot server to be able to exploit this vulnerability successfully.
Scoring
| CVSS | 8.3 () |
| Vector | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H |
| Last modified | 2026-06-26 |