CVE-2022-32953
📋 TL;DR
This vulnerability in Insyde InsydeH2O firmware allows DMA attacks on the SdHostDriver buffer, creating TOCTOU race conditions that can corrupt SMRAM and lead to privilege escalation. It affects systems with InsydeH2O kernel versions 5.0 through 5.5. Attackers with physical access or DMA capabilities can exploit this to gain elevated privileges.
💻 Affected Systems
- Insyde InsydeH2O UEFI firmware
📦 What is this software?
Insydeh2o by Insyde
Insydeh2o by Insyde
Insydeh2o by Insyde
Insydeh2o by Insyde
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with SMM-level code execution, allowing attackers to bypass all security controls, install persistent malware, and access sensitive data.
Likely Case
Local privilege escalation from user to kernel or SMM level, enabling installation of rootkits or credential theft.
If Mitigated
Limited impact with proper IOMMU protection and SMRAM validation in place, preventing successful exploitation.
🎯 Exploit Status
Exploitation requires DMA access and precise timing for TOCTOU race conditions, making it technically challenging.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel version 5.6 or later
Vendor Advisory: https://www.insyde.com/security-pledge/SA-2023013
Restart Required: Yes
Instructions:
1. Check with device manufacturer for firmware update availability. 2. Download latest firmware from manufacturer support site. 3. Follow manufacturer's firmware update instructions. 4. Reboot system to apply update.
🔧 Temporary Workarounds
Enable IOMMU protection
allConfigure IOMMU to protect ACPI runtime memory used for command buffer
Enable VT-d/AMD-Vi in BIOS/UEFI settings
Configure kernel parameters: intel_iommu=on or amd_iommu=on
Implement SMRAM validation
allCopy link data to SMRAM before checking and verify all pointers are within buffer
Requires firmware modification - contact vendor for implementation
🧯 If You Can't Patch
- Restrict physical access to systems to prevent DMA attacks
- Disable Thunderbolt/DMA-capable ports in BIOS/UEFI settings
🔍 How to Verify
Check if Vulnerable:
Check firmware version in UEFI/BIOS settings or using manufacturer's system information toolCheck Version:
Manufacturer-specific commands vary - check with OEM documentationVerify Fix Applied:
Verify firmware version is 5.6 or later in UEFI/BIOS settings📡 Detection & Monitoring
Log Indicators:
- Unexpected SMM transitions
- Firmware modification attempts
- DMA access violations
Network Indicators:
- Not network exploitable - no network indicators
SIEM Query:
Event ID related to firmware/SMM access or DMA operations