CVE-2022-29276 in insyde
Summary
by MITRE • 11/16/2022
SMI functions in AhciBusDxe use untrusted inputs leading to corruption of SMRAM. SMI functions in AhciBusDxe use untrusted inputs leading to corruption of SMRAM. This issue was discovered by Insyde during security review. It was fixed in: Kernel 5.0: version 05.09.18 Kernel 5.1: version 05.17.18 Kernel 5.2: version 05.27.18 Kernel 5.3: version 05.36.18 Kernel 5.4: version 05.44.18 Kernel 5.5: version 05.52.18 https://www.insyde.com/security-pledge/SA-2022059
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Analysis
by VulDB Data Team • 05/22/2026
The vulnerability identified as CVE-2022-29276 represents a critical security flaw within the Advanced Host Controller Interface (AHCI) bus driver implementation in UEFI firmware environments. This issue specifically affects the AhciBusDxe module which handles storage controller operations during the Unified Extensible Firmware Interface boot process. The vulnerability stems from improper validation of inputs received during System Management Interrupt (SMI) handler execution, creating a pathway for malicious actors to manipulate system memory regions. The flaw was discovered through systematic security review activities conducted by Insyde, a leading firmware security company, highlighting the importance of thorough code analysis in firmware development environments where security considerations are paramount.
The technical exploitation of this vulnerability occurs when SMI functions within the AhciBusDxe module process untrusted input data without adequate sanitization or validation checks. This allows attackers to potentially corrupt the System Management RAM (SMRAM) which serves as a protected memory region where critical system management code executes with the highest privilege levels. The SMRAM corruption represents a severe compromise since this memory area contains the firmware's core operational code and sensitive system state information that should remain isolated from normal operating system activities. When untrusted inputs are processed through SMI handlers without proper boundary checks, the vulnerability enables attackers to manipulate memory contents that should be protected from external interference, creating potential for privilege escalation and system compromise.
The operational impact of CVE-2022-29276 extends beyond simple memory corruption, as it fundamentally undermines the security model of UEFI firmware implementations. When attackers can corrupt SMRAM through SMI handler vulnerabilities, they gain access to privileged execution environments where normal memory protection mechanisms are bypassed. This creates opportunities for persistent malware deployment, credential theft, and complete system compromise that can persist across reboots since firmware-level modifications remain undetected by traditional operating system security measures. The vulnerability affects multiple kernel versions across the 5.0 through 5.5 release lines, indicating a widespread issue within the affected firmware implementations that required coordinated patching efforts across different kernel versions to address the root cause in the AHCI bus driver SMI handling code.
The mitigation strategy for this vulnerability involves applying the firmware patches released by Insyde as referenced in their security advisory SA-2022059, which specifically addresses the untrusted input processing in the AhciBusDxe module. System administrators should ensure that all affected firmware versions are updated to the patched versions indicated for each kernel release, with particular attention to maintaining consistent patching across all system components that utilize AHCI storage controllers. This vulnerability aligns with CWE-129, which describes improper validation of input boundaries, and represents a classic example of how firmware security flaws can create persistent attack vectors that operate below the level of traditional operating system security controls. The remediation process requires careful validation of firmware updates to ensure that the specific SMI handler modifications are properly implemented and that no additional vulnerabilities were introduced during the patching process, as the complexity of firmware security updates often introduces new risk vectors that must be carefully evaluated.