CVE-2022-40246 is a high-severity vulnerability classified as CWE-123 (Write-What-Where Condition) affecting AMI's Aptio firmware, specifically version 5.x. This flaw occurs during the Pre-EFI Initialization (PEI) phase of the boot process, but only when the system resumes from the S3 sleep state. The vulnerability allows an attacker with high privileges (PR:H) and physical access (AV:P) to write a single byte to an arbitrary memory address. This seemingly minor write capability can be leveraged to manipulate subsequent boot stages, potentially bypassing security mitigations designed to protect memory confidentiality and integrity. Exploitation could lead to disclosure of physical memory contents, including secrets from any virtual machines running on the system, effectively breaking memory isolation and confidential computing boundaries. Furthermore, an attacker could craft a payload to be injected into the System Management RAM (SMRAM), which is a highly privileged memory region used by system firmware for critical management tasks. The vulnerability's CVSS 3.1 score is 7.2 (High), reflecting its significant impact on confidentiality, integrity, and availability, with a complex scope due to the potential to affect multiple system components and virtualized environments. Exploitation requires physical access and high privileges, but no user interaction is needed. No known exploits are currently reported in the wild, and no patches have been linked yet. The affected module is SbPei with a specific SHA256 hash and GUID, indicating a precise firmware component is vulnerable. This vulnerability is particularly dangerous because it undermines foundational security assumptions in modern computing platforms, especially those relying on trusted boot and confidential computing technologies.

For European organizations, the impact of CVE-2022-40246 could be severe, especially for enterprises relying on AMI Aptio firmware in their server and workstation infrastructure. The ability to bypass memory isolation and extract secrets from virtual machines threatens confidentiality of sensitive data, including intellectual property, personal data protected under GDPR, and cryptographic keys. This could lead to data breaches, regulatory penalties, and loss of customer trust. The injection of malicious payloads into SMRAM could enable persistent firmware-level malware, which is notoriously difficult to detect and remediate, potentially leading to long-term compromise of critical systems. Organizations utilizing confidential computing environments for secure processing would be at risk of having their security boundaries violated. The requirement for physical access limits remote exploitation but raises concerns for data centers, branch offices, and environments where physical security might be less stringent. The vulnerability could also disrupt availability if exploited to corrupt boot processes, causing system instability or denial of service. Overall, this vulnerability poses a significant threat to the security posture of European enterprises, especially those in finance, government, healthcare, and cloud service providers that depend on secure virtualization and trusted platform modules.

Given the absence of an official patch link, European organizations should take immediate steps to mitigate risk. First, enforce strict physical security controls to prevent unauthorized access to systems, including locked server rooms and surveillance. Second, implement firmware integrity verification mechanisms such as measured boot and trusted platform module (TPM) attestation to detect unauthorized modifications during boot. Third, restrict S3 sleep state usage or disable it where feasible, as the vulnerability is exploitable only during S3 resume. Fourth, monitor firmware versions and subscribe to AMI security advisories to apply patches promptly once available. Fifth, employ runtime memory protection and virtualization-based security features that can limit the impact of firmware-level compromises. Sixth, conduct regular firmware audits and penetration testing focusing on boot process security. Finally, consider hardware replacement or firmware upgrades for systems running vulnerable Aptio versions if patches are delayed, prioritizing critical infrastructure. These measures, combined, reduce the attack surface and improve detection and response capabilities against exploitation attempts.