#VU86236 Insufficient verification of data authenticity in Shim - CVE-2023-40547
Published: February 7, 2024
Vulnerability identifier: #VU86236
Vulnerability risk: High
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2023-40547
CWE-ID: CWE-345
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Shim
Shim
Software vendor:
Red Hat Bootloader Team
Red Hat Bootloader Team
Description
The vulnerability allows a remote attacker to compromise the affected system.
The vulnerability exists due to missing verification of data authenticity when parsing HTTP responses. A remote attacker can perform a man-in-the-middle (MitM) attack and use 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.
Remediation
Install updates from vendor's website.