CVE-2022-33909 is a high-severity vulnerability involving a Time-Of-Check to Time-Of-Use (TOCTOU) race condition in the handling of Direct Memory Access (DMA) transactions targeting input buffers used by the HddPassword software System Management Interrupt (SMI) handler. Specifically, this vulnerability allows malicious DMA transactions to corrupt System Management RAM (SMRAM) by exploiting a timing window in the software SMI handler's input buffer processing. The HddPassword driver, which is involved in managing hard disk password functionality, uses software SMIs to handle certain operations. However, due to insufficient synchronization or validation, an attacker with the ability to initiate DMA transactions can manipulate the input buffers during the TOCTOU window, leading to SMRAM corruption. SMRAM is a highly privileged memory region used by the system firmware (System Management Mode) to execute critical code isolated from the operating system and other software layers. Corruption of SMRAM can lead to severe consequences including privilege escalation, arbitrary code execution at the firmware level, and potential compromise of the entire system. The vulnerability was discovered by Insyde engineering, based on Intel iSTARE group’s general description, and affects multiple kernel versions (5.2, 5.3, 5.4, 5.5) with fixes released in May 2023. The CVSS v3.1 score is 7.0, reflecting high impact on confidentiality, integrity, and availability, with attack vector local (requiring local access), high attack complexity, low privileges required, and no user interaction needed. The vulnerability is classified under CWE-367 (Time-of-check Time-of-use race condition). No known exploits are reported in the wild as of the published date. This vulnerability is particularly critical because it targets firmware-level memory, which is foundational to system security and isolation.

For European organizations, the impact of CVE-2022-33909 can be significant, especially for enterprises relying on hardware platforms that use the affected HddPassword driver and corresponding firmware implementations. Successful exploitation could allow attackers with local access (e.g., via compromised internal systems, malicious insiders, or attackers with physical access) to corrupt SMRAM, potentially leading to firmware-level compromise. This can result in persistent, stealthy malware that survives OS reinstallation or disk replacement, undermining endpoint security and trust. Critical infrastructure sectors such as finance, healthcare, manufacturing, and government agencies in Europe could face severe operational disruptions, data breaches, and loss of system integrity. The high privilege level of SMRAM corruption means attackers could bypass traditional security controls, making detection and remediation challenging. Moreover, organizations with remote or hybrid workforces that allow local access to sensitive systems may be at increased risk. Although no exploits are currently known in the wild, the vulnerability’s nature and high impact necessitate proactive mitigation to prevent future targeted attacks or supply chain compromises.

To mitigate CVE-2022-33909 effectively, European organizations should: 1) Ensure all affected systems are updated with the latest kernel patches released in May 2023 (Kernel versions 5.2, 5.3, 5.4, 5.5) that address this vulnerability. 2) Conduct an inventory of hardware platforms and firmware versions to identify devices using the vulnerable HddPassword driver and verify firmware updates from vendors. 3) Restrict and monitor local access to critical systems, enforcing strict access controls and physical security to prevent unauthorized DMA-capable devices or malicious insiders from initiating DMA transactions. 4) Employ Input-Output Memory Management Units (IOMMUs) where possible to restrict DMA access to authorized memory regions, thereby mitigating unauthorized DMA transactions. 5) Implement endpoint detection and response (EDR) solutions capable of monitoring unusual system management mode activities or firmware anomalies. 6) Coordinate with hardware and firmware vendors to ensure timely deployment of firmware updates and validate that mitigations are effective. 7) Educate IT and security teams about the risks of firmware-level attacks and the importance of securing local access vectors. 8) For high-security environments, consider hardware-based protections such as enabling Intel Boot Guard or equivalent technologies to protect SMRAM integrity.