CVE-2023-23904 is a vulnerability identified in the UEFI firmware of certain Intel processors, characterized by a NULL pointer dereference that can be exploited by a privileged local user to escalate their privileges. The UEFI (Unified Extensible Firmware Interface) is a critical low-level firmware interface responsible for initializing hardware and bootstrapping the operating system. A NULL pointer dereference in this context indicates that the firmware improperly handles a pointer that is expected to reference a valid memory location but instead is NULL, leading to undefined behavior that can be leveraged to elevate privileges. The vulnerability requires an attacker to already have high privileges on the system and local access, meaning remote exploitation is not feasible. The CVSS 4.0 vector (AV:L/AC:H/AT:P/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L) indicates that the attack vector is local, with high attack complexity, requiring privileges and partial user interaction is not needed. The impact primarily affects system integrity and availability, as an attacker could manipulate firmware execution or cause system instability. No known exploits have been reported in the wild, but the vulnerability poses a risk in environments where multiple users have elevated privileges or where firmware security is critical. The affected versions are not explicitly listed but pertain to certain Intel processors’ UEFI firmware, emphasizing the need for organizations to consult Intel advisories for specific patch information.

For European organizations, the impact of CVE-2023-23904 can be significant in environments where Intel processors are widely deployed, particularly in enterprise servers, workstations, and critical infrastructure systems. The ability for a privileged local user to escalate privileges within the firmware layer can undermine system integrity and potentially disrupt availability, leading to operational downtime or unauthorized control over hardware initialization processes. This could facilitate further attacks such as persistent malware implantation or bypassing security controls enforced at the OS level. Organizations in sectors like finance, government, telecommunications, and manufacturing, which rely heavily on Intel hardware and have complex user privilege models, are at increased risk. The requirement for local privileged access limits the threat to insider threats or attackers who have already compromised user accounts with elevated rights. However, given the firmware-level nature of the vulnerability, remediation is complex and requires coordinated firmware updates, which may impact system availability during patching. Failure to address this vulnerability could lead to increased risk of sophisticated attacks that compromise foundational system security.

1. Apply firmware updates from Intel or system vendors as soon as they become available to address this vulnerability. 2. Restrict and monitor privileged local user accounts rigorously to minimize the risk of insider threats exploiting this flaw. 3. Implement strict access controls and use endpoint security solutions to detect and prevent unauthorized privilege escalations. 4. Employ hardware-based security features such as Intel Boot Guard and Trusted Platform Module (TPM) to enhance firmware integrity verification. 5. Conduct regular security audits and firmware integrity checks to detect anomalies indicative of exploitation attempts. 6. Coordinate patching schedules carefully to minimize downtime, especially in critical infrastructure environments. 7. Educate system administrators and security teams about the risks associated with firmware vulnerabilities and the importance of timely updates. 8. Use multi-factor authentication and least privilege principles to reduce the likelihood of privileged account compromise. 9. Maintain an inventory of affected hardware to prioritize patching efforts effectively. 10. Monitor vendor advisories and threat intelligence feeds for updates on exploit developments or additional mitigations.