CVE-2022-33982 is a vulnerability involving Direct Memory Access (DMA) attacks targeting the parameter buffer used by the Int15ServiceSmm software System Management Interrupt (SMI) handler. The vulnerability arises from a Time-Of-Check to Time-Of-Use (TOCTOU) race condition in the SMI handler, which can be exploited by manipulating the parameter buffer via DMA. This manipulation can lead to corruption of the System Management RAM (SMRAM), a highly privileged memory region used by the System Management Mode (SMM) firmware to execute critical low-level code isolated from the operating system. The vulnerability was discovered by Insyde engineering during a security review and is associated with CWE-367 (Time-of-check Time-of-use Race Condition). The issue affects certain kernel versions prior to the fixed releases in Kernel 5.2 (05.27.23), 5.3 (05.36.23), 5.4 (05.44.23), and 5.5 (05.52.23). Exploiting this vulnerability requires local access with high privileges, as indicated by the CVSS vector (AV:L/AC:H/PR:H/UI:N), and no user interaction is needed. Successful exploitation can lead to high impact on confidentiality, integrity, and availability of the system by corrupting SMRAM, potentially allowing attackers to execute arbitrary code at the highest privilege level, bypassing OS-level security controls. There are no known exploits in the wild as of the publication date, and no specific vendor or product is identified, suggesting this vulnerability may affect firmware components or drivers common in systems using Insyde firmware or similar SMM handlers. The vulnerability is rated medium severity with a CVSS score of 6.4 due to the complexity of exploitation and required privileges.

For European organizations, the impact of CVE-2022-33982 can be significant, particularly for enterprises relying on hardware and firmware components that utilize the Int15ServiceSmm driver or similar SMM handlers. Successful exploitation could allow attackers with local high privileges to corrupt SMRAM, potentially leading to persistent firmware-level compromise, bypassing OS security, and gaining control over critical system functions. This could result in data breaches, disruption of critical services, or sabotage of industrial control systems. Sectors such as finance, critical infrastructure, manufacturing, and government agencies in Europe are at higher risk due to their reliance on secure firmware and hardware integrity. The requirement for high privileges and local access reduces the likelihood of remote exploitation but does not eliminate risk from insider threats or attackers who have already gained initial footholds. The lack of known exploits suggests limited immediate threat but underscores the importance of patching to prevent future targeted attacks. The potential for SMRAM corruption also raises concerns for system stability and availability, which can disrupt business continuity.

1. Apply firmware and kernel updates promptly: European organizations should ensure that systems are updated to the fixed kernel versions (5.2: 05.27.23, 5.3: 05.36.23, 5.4: 05.44.23, 5.5: 05.52.23) or later, which address this vulnerability. 2. Restrict physical and local access: Since exploitation requires local high privileges and DMA capabilities, organizations should enforce strict physical security controls and limit administrative access to trusted personnel only. 3. Enable Input-Output Memory Management Unit (IOMMU): Configuring IOMMU can help mitigate unauthorized DMA attacks by restricting device access to memory regions, thereby protecting SMRAM from malicious DMA operations. 4. Monitor for anomalous SMM activity: Deploy advanced endpoint detection and response (EDR) tools capable of detecting unusual SMM handler behavior or memory corruption attempts. 5. Conduct firmware integrity checks: Regularly verify firmware integrity using cryptographic validation to detect unauthorized modifications to SMRAM or SMM code. 6. Implement strict privilege management: Enforce least privilege principles and multi-factor authentication for administrative accounts to reduce the risk of privilege escalation that could lead to exploitation. 7. Collaborate with hardware vendors: Engage with hardware and firmware suppliers to confirm vulnerability status and obtain vendor-specific patches or mitigations if available.