CVE-2022-30774 describes a Time-Of-Check to Time-Of-Use (TOCTOU) vulnerability in the PnpSmm driver, which is part of the system management mode (SMM) firmware environment. The vulnerability arises from the use of a parameter buffer that is susceptible to Direct Memory Access (DMA) attacks. Specifically, after the parameter values have been validated (checked), an attacker with DMA capabilities can alter the contents of the buffer before these parameters are actually used by the driver. This race condition allows an attacker to bypass security checks and potentially execute malicious actions with elevated privileges. The flaw was identified by Insyde engineering during a security review and is classified under CWE-367 (Time-of-check Time-of-use Race Condition). The vulnerability affects multiple kernel versions, including Kernel 5.2 (05.27.29), 5.3 (05.36.25), 5.4 (05.44.25), and 5.5 (05.52.25), with fixes applied in these versions. The CVSS v3.1 base score is 6.4, indicating a medium severity level. The attack vector is local (AV:L), requiring high attack complexity (AC:H) and high privileges (PR:H), with no user interaction (UI:N). The impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), meaning successful exploitation could lead to significant compromise of system security. No known exploits are currently in the wild, and no specific vendor or product details are provided, but the vulnerability is related to firmware-level components, which are critical for system security and stability.

For European organizations, the impact of CVE-2022-30774 could be substantial, particularly for entities relying on affected kernel versions and systems utilizing the vulnerable PnpSmm driver. Since the vulnerability allows an attacker with local high privileges and DMA access to manipulate critical parameters post-validation, it could lead to unauthorized code execution, privilege escalation, or system compromise at the firmware level. This could undermine the confidentiality, integrity, and availability of sensitive data and critical infrastructure. Sectors such as finance, healthcare, manufacturing, and government agencies in Europe, which often use high-assurance systems with stringent security requirements, could face risks of data breaches, operational disruption, or espionage. The requirement for local access and high privileges limits the attack surface but does not eliminate risk, especially in environments where insider threats or compromised devices exist. Given the firmware-level nature of the vulnerability, remediation is complex and may require coordinated firmware and kernel updates, which could impact operational continuity if not managed carefully.

1. Ensure all systems are updated to the fixed kernel versions: 5.2 (05.27.29), 5.3 (05.36.25), 5.4 (05.44.25), or 5.5 (05.52.25) or later, as these contain patches addressing the vulnerability. 2. Restrict and monitor physical and local access to systems, especially those with DMA-capable interfaces (e.g., Thunderbolt, PCIe), to prevent unauthorized DMA attacks. 3. Implement Input-Output Memory Management Unit (IOMMU) protections to restrict DMA access to trusted devices only, mitigating the risk of unauthorized memory manipulation. 4. Conduct thorough audits of firmware and driver versions across organizational assets to identify vulnerable systems and prioritize patching. 5. Employ endpoint detection and response (EDR) solutions capable of detecting anomalous behavior indicative of firmware-level attacks or privilege escalations. 6. Coordinate with hardware vendors and firmware providers to ensure timely updates and validate the integrity of firmware components. 7. For critical infrastructure, consider network segmentation and strict access controls to limit the potential impact of compromised devices. 8. Educate system administrators and security teams about the risks of DMA attacks and the importance of maintaining updated firmware and kernel versions.