CVE-2022-32955
📋 TL;DR
This vulnerability in Insyde InsydeH2O firmware allows DMA attacks on the NvmExpressDxe 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 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 privileges, allowing attackers to bypass all security controls, install persistent malware, and access all system memory and hardware.
Likely Case
Local privilege escalation from user to kernel or SMM level, enabling installation of rootkits, credential theft, and persistence mechanisms.
If Mitigated
Attack requires physical access or DMA capabilities; with IOMMU protection and proper buffer handling, exploitation becomes significantly more difficult.
🎯 Exploit Status
Exploitation requires physical access or DMA capabilities, understanding of SMM and firmware internals, and precise timing for TOCTOU race conditions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel version 5.6 or later
Vendor Advisory: https://www.insyde.com/security-pledge/SA-2023015
Restart Required: Yes
Instructions:
1. Check with your device manufacturer for BIOS/UEFI firmware updates. 2. Download the updated firmware from manufacturer's support site. 3. Follow manufacturer's instructions to flash the updated firmware. 4. Reboot the system to apply changes.
🔧 Temporary Workarounds
Enable IOMMU/DMA Protection
allConfigure system to use IOMMU protection for ACPI runtime memory used for command buffers
Check BIOS/UEFI settings for VT-d/AMD-Vi/IOMMU options and enable them
Restrict Physical Access
allImplement physical security controls to prevent unauthorized DMA access
Use chassis intrusion detection
Secure physical ports with locks
Implement device control policies
🧯 If You Can't Patch
- Implement strict physical security controls and monitor for unauthorized physical access
- Disable or restrict Thunderbolt/DMA-capable ports in BIOS/UEFI settings where possible
🔍 How to Verify
Check if Vulnerable:
Check firmware version in BIOS/UEFI settings or using system information tools. On Windows: wmic bios get smbiosbiosversion. On Linux: dmidecode -t biosCheck Version:
Windows: wmic bios get smbiosbiosversion | Linux: dmidecode -t bios | grep -i versionVerify Fix Applied:
Verify firmware version is 5.6 or later after update. Check that IOMMU/DMA protection is enabled in BIOS settings.📡 Detection & Monitoring
Log Indicators:
- BIOS/UEFI firmware modification events
- SMM-related errors in system logs
- Unexpected DMA access attempts
Network Indicators:
- Not network exploitable - focus on physical access monitoring
SIEM Query:
Event ID 1 (System boot) with unexpected firmware changes OR Security logs showing physical access violations