CVE-2022-24030: Insyde InsydeH2O Privilege Escalation Flaw

CVE-2022-24030 Overview

CVE-2022-24030 is a critical UEFI firmware vulnerability discovered in the AhciBusDxe driver of Insyde InsydeH2O BIOS firmware. This SMM (System Management Mode) memory corruption vulnerability affects InsydeH2O kernels 5.1 through 5.5 and allows an attacker with elevated local privileges to write fixed or predictable data to SMRAM (System Management RAM). Successful exploitation could enable privilege escalation to SMM, one of the most privileged execution modes on x86 systems.

SMM operates at a higher privilege level than the operating system kernel or hypervisor, making vulnerabilities in this execution mode particularly dangerous. Attackers who gain SMM access can bypass security controls, install persistent implants that survive OS reinstallation, and compromise the entire trust chain of the system.

Critical Impact

Exploitation allows attackers to escalate privileges to System Management Mode (SMM), enabling persistent firmware-level compromise that survives OS reinstallation and can bypass security controls including Secure Boot.

Affected Products

• Insyde InsydeH2O with kernel 5.1
• Insyde InsydeH2O with kernel 5.2
• Insyde InsydeH2O with kernel 5.3
• Insyde InsydeH2O with kernel 5.4
• Insyde InsydeH2O with kernel 5.5

Discovery Timeline

• February 3, 2022 - CVE CVE-2022-24030 published to NVD
• November 4, 2025 - Last updated in NVD database

Technical Details for CVE-2022-24030

Vulnerability Analysis

This vulnerability resides in the AhciBusDxe driver, which provides AHCI (Advanced Host Controller Interface) bus support during the UEFI boot process. The flaw is classified as CWE-787 (Out-of-Bounds Write), indicating that the driver fails to properly validate memory boundaries before performing write operations.

The vulnerability allows an attacker to corrupt SMRAM contents by writing fixed or predictable data to memory regions that should be protected. SMRAM is a dedicated memory region used exclusively by SMM code and is intended to be isolated from all other software running on the system, including the operating system and hypervisor.

When the vulnerability is exploited, an attacker can modify SMM handler code or data structures stored in SMRAM. Since SMM executes with ring -2 privileges (below the hypervisor at ring -1 and the kernel at ring 0), code running in SMM has unrestricted access to all system resources including hardware, memory, and CPU registers.

Root Cause

The root cause is an out-of-bounds write condition (CWE-787) in the AhciBusDxe driver's memory handling routines. The driver fails to properly validate input parameters or buffer boundaries when interacting with SMRAM regions, allowing an attacker to craft malicious inputs that cause writes to protected memory areas.

This type of vulnerability typically occurs when:

• Buffer size calculations do not account for all edge cases
• Pointer arithmetic is performed without proper bounds checking
• Memory copy operations use attacker-controlled length values without validation
• Index values are not validated against array bounds

Attack Vector

The attack vector is local, requiring the attacker to have high privileges on the affected system. The attacker must be able to interact with the UEFI firmware, either through direct hardware access, a compromised operating system with kernel-level privileges, or during the boot process.

The exploitation scenario involves crafting malicious data that triggers the out-of-bounds write condition in the AhciBusDxe driver. Because the write target is SMRAM and the written data is fixed or predictable, the attacker can potentially:

1. Overwrite SMM handler entry points to redirect execution to attacker-controlled code
2. Modify SMM data structures to disable security checks
3. Install persistent backdoors that execute in SMM context
4. Bypass firmware-based security features including Secure Boot

For technical details on the vulnerability mechanism and exploitation, refer to the Insyde Security Advisory SA-2022011 and CERT Vulnerability Note VU#796611.

Detection Methods for CVE-2022-24030

Indicators of Compromise

• Unexpected modifications to UEFI firmware or NVRAM variables
• Anomalous SMI (System Management Interrupt) activity during boot or runtime
• Integrity check failures on firmware components or bootloader
• Presence of unauthorized or modified UEFI drivers in the firmware volume

Detection Strategies

• Implement firmware integrity monitoring using hardware-based attestation (TPM)
• Deploy runtime firmware scanning solutions that can detect SMRAM modifications
• Monitor for suspicious privileged operations targeting firmware interfaces
• Use SentinelOne's firmware visibility capabilities to detect unauthorized firmware changes

Monitoring Recommendations

• Enable and monitor UEFI Secure Boot violation events in system logs
• Configure alerting for failed firmware integrity checks during boot attestation
• Monitor for kernel-mode drivers attempting to access UEFI runtime services inappropriately
• Review system event logs for unexpected SMI handler invocations

How to Mitigate CVE-2022-24030

Immediate Actions Required

• Update affected Insyde InsydeH2O firmware to the latest patched version from your OEM vendor
• Verify UEFI Secure Boot is enabled and properly configured
• Restrict physical access to affected systems
• Limit local administrative privileges to reduce the attack surface

Patch Information

Insyde has released firmware updates addressing this vulnerability. As InsydeH2O is provided through OEM vendors (such as Siemens, NetApp, and numerous PC manufacturers), patches must be obtained from the specific hardware vendor. Consult the following resources for patch availability:

• Insyde Security Advisory SA-2022011 for official vendor guidance
• Siemens Security Advisory SSA-306654 for affected Siemens products
• NetApp Security Advisory NTAP-20220216-0011 for affected NetApp systems

Contact your OEM vendor for specific firmware update availability and installation instructions.

Workarounds

• Enable UEFI Secure Boot to help prevent unauthorized firmware modifications
• Implement firmware write protection if available on your hardware platform
• Use hardware security modules (HSM) or TPM-based measured boot to detect tampering
• Consider network segmentation to isolate systems that cannot be immediately patched

# Verify UEFI Secure Boot status (Linux)
mokutil --sb-state

# Check for available firmware updates (Linux with fwupd)
fwupdmgr get-updates
fwupdmgr update

# On Windows, use PowerShell to verify Secure Boot
Confirm-SecureBootUEFI