CVE-2022-33982 in insyde
Summary
by MITRE • 11/15/2022
DMA attacks on the parameter buffer used by the Int15ServiceSmm software SMI handler could lead to a TOCTOU attack on the SMI handler and lead to corruption of SMRAM. DMA attacks on the parameter buffer used by the software SMI handler used by the driver Int15ServiceSmm could lead to a TOCTOU attack on the SMI handler and lead to corruption of SMRAM. This issue was discovered by Insyde engineering during a security review. This issue is fixed in Kernel 5.2: 05.27.23, Kernel 5.3: 05.36.23, Kernel 5.4: 05.44.23 and Kernel 5.5: 05.52.23 CWE-367
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Analysis
by VulDB Data Team • 06/12/2026
The vulnerability described in CVE-2022-33982 represents a critical security flaw in the Int15ServiceSmm software SMI handler component of certain firmware implementations. This issue specifically targets the parameter buffer utilized by the SMI handler, creating a dangerous attack surface that allows for sophisticated DMA-based exploitation techniques. The vulnerability was identified through internal security reviews conducted by Insyde engineering, highlighting the importance of comprehensive firmware security assessments in modern computing environments where hardware-level attacks can bypass traditional software security controls.
The technical implementation of this vulnerability stems from a Time-of-Check to Time-of-Use (TOCTOU) race condition within the SMI handler's parameter buffer management. When the Int15ServiceSmm driver processes SMI requests, it maintains a parameter buffer that is accessible through DMA operations, creating an opportunity for malicious actors to manipulate the buffer contents between the time the SMI handler validates the parameters and when it actually processes them. This race condition allows attackers to potentially modify buffer contents during the brief window between validation and execution, ultimately leading to unauthorized modification of SMRAM memory regions.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to corrupt SMRAM (System Management RAM) which contains sensitive system information and firmware code. SMRAM corruption can result in complete system compromise, as this memory region typically stores critical firmware components, cryptographic keys, and system state information that is protected from normal operating system access. The vulnerability's exploitation requires DMA capabilities, which can be achieved through various attack vectors including malicious USB devices, PCIe cards, or other hardware interfaces that support direct memory access operations, making it particularly concerning for systems with exposed DMA interfaces.
This vulnerability aligns with CWE-367, which specifically addresses the Time-of-Check to Time-of-Use flaw in security contexts, and represents a significant concern within the ATT&CK framework under the T1068 technique for exploit for privilege escalation. The remediation strategy implemented by the affected vendors involved updating kernel versions to specific release dates, with fixes rolled out across kernel versions 5.2 through 5.5. The patch addresses the core issue by implementing proper synchronization mechanisms and buffer validation checks that prevent the race condition from being exploited. Organizations should prioritize these kernel updates as part of their firmware security maintenance procedures, while also implementing hardware-level mitigations such as DMA protection features and ensuring that firmware components undergo rigorous security review processes before deployment.
The discovery and subsequent patching of this vulnerability demonstrates the ongoing challenges in securing firmware components, particularly those that operate at the system management level where traditional software security controls are ineffective. This issue underscores the critical need for continuous security assessments of firmware components, as well as the importance of implementing proper access controls and validation mechanisms in low-level system components that handle sensitive operations. The vulnerability also highlights the necessity for hardware vendors to implement robust security features that prevent unauthorized DMA access to critical system memory regions, particularly in environments where physical security cannot be guaranteed.