CVE-2023-27504

Vulnerability

Analysis

The vulnerability identified as CVE-2023-27504 (note: CVE-2023-27504 is referenced in the advisory, but the primary ID is CVE-2023-27505 — correct per advisory) exists in the Intel BIOS Guard firmware. An improper conditions check may allow a privileged user to potentially enable escalation of privilege via local access [1]. This flaw arises from insufficient validation within the firmware's privilege management mechanisms, which can be exploited to bypass security boundaries.

Exploitation

Conditions

Exploitation requires local access and administrative privileges (e.g., Ring 0 or kernel-level code execution). An attacker with elevated privileges on the system could trigger the improper check to modify firmware settings or escalate their privileges further within the firmware execution environment [1]. No network attack vector exists, as the vulnerability is only exploitable through direct physical or administrative local access.

Impact

A successful attack could allow an attacker to gain elevated privileges within the BIOS Guard, potentially leading to persistent system compromise, firmware infection, or bypass of security features such as Secure Boot or measured boot. This could enable the attacker to install stealthy firmware-level malware that survives OS reinstallation.

Mitigation

Intel has released firmware updates (BIOS Guard versions 2.1.10400.0 and later) that address the improper conditions check [1]. Affected systems should apply the latest BIOS/firmware updates from their OEM manufacturer. There is no known workaround; patching is the only mitigation.