SB2024081421 - Microsoft Windows update for Red Hat Shim

Description

This security bulletin contains information about 1 security vulnerability.

1) Insufficient verification of data authenticity (CVE-ID: CVE-2023-40547)

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 update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-40547