CVE-2022-32474 in InsydeH2O
Summary
by MITRE • 02/15/2023
An issue was discovered in Insyde InsydeH2O with kernel 5.0 through 5.5. DMA attacks on the StorageSecurityCommandDxe shared buffer used by SMM and non-SMM code could cause TOCTOU race-condition issues that could lead to corruption of SMRAM and escalation of privileges. This attack can be mitigated using IOMMU protection for the ACPI runtime memory used for the command buffer. This attack can be mitigated by copying the firmware block services data to SMRAM before checking it.
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Analysis
by VulDB Data Team • 05/29/2026
The vulnerability identified as CVE-2022-32474 represents a critical security flaw in Insyde InsydeH2O firmware implementations running kernel versions 5.0 through 5.5. This issue stems from improper handling of shared memory buffers within the System Management Mode architecture, specifically affecting the StorageSecurityCommandDxe driver component. The flaw creates a time-of-check to time-of-use race condition that enables malicious actors to exploit the shared buffer between SMM and non-SMM execution contexts. Such vulnerabilities are particularly dangerous because they operate at the firmware level where traditional operating system security controls are bypassed, making them difficult to detect and mitigate through conventional means.
The technical implementation of this vulnerability involves a DMA attack vector that targets the StorageSecurityCommandDxe shared buffer, which serves as a communication channel between SMM and standard execution modes. When the firmware processes storage security commands, it utilizes this shared buffer to store and retrieve data, but the lack of proper synchronization mechanisms creates a window where malicious actors can manipulate the buffer contents between the initial validation check and the actual data processing. This race condition allows attackers to corrupt the System Management RAM (SMRAM) which contains critical firmware code and data that should remain protected from unauthorized modification. The vulnerability directly maps to CWE-367 Time-of-Check to Time-of-Use (TOCTOU) weakness category, which is classified under the broader category of improper handling of synchronization primitives in security-critical code segments.
The operational impact of this vulnerability extends beyond simple privilege escalation to include potential complete system compromise and persistent backdoor capabilities. Attackers who successfully exploit this vulnerability can gain elevated privileges within the firmware environment, potentially allowing them to modify critical firmware components, install rootkits, or establish persistent access to the system. The attack can be executed through DMA capabilities, which means that an attacker with physical access to a system or the ability to execute DMA attacks through peripheral devices can exploit this vulnerability without requiring network connectivity or complex remote attack vectors. This makes the vulnerability particularly concerning for enterprise environments where physical security controls may be insufficient. The ATT&CK framework categorizes this as a firmware-level attack technique, specifically under the T1542.001 technique for "System Firmware" where attackers modify system firmware to maintain persistence.
Mitigation strategies for this vulnerability must address both the immediate architectural flaw and implement broader security controls. The primary recommended mitigation involves enabling IOMMU (Input-Output Memory Management Unit) protection for the ACPI runtime memory used for the command buffer, which prevents unauthorized DMA access to critical firmware memory regions. Additionally, implementing proper data copying mechanisms that move firmware block services data to SMRAM before validation eliminates the race condition window. Organizations should also consider firmware update procedures to ensure all systems are running patched versions of the InsydeH2O firmware that address this specific vulnerability. The implementation of these mitigations aligns with industry best practices for firmware security and follows recommendations from organizations such as the National Institute of Standards and Technology (NIST) for protecting against firmware-level attacks. Security teams should also implement continuous monitoring for unauthorized firmware modifications and establish secure boot processes that can detect and prevent exploitation attempts.