CVE-2024-49200
📋 TL;DR
This vulnerability allows attackers to perform arbitrary writes in DXE memory by manipulating NVRAM variables, potentially leading to arbitrary code execution. It affects Insyde InsydeH2O firmware with kernel versions 5.2 through 5.7. Systems using this firmware are vulnerable during the DXE boot phase before OS loading.
💻 Affected Systems
- Insyde InsydeH2O firmware
📦 What is this software?
Kernel by Insyde
Kernel by Insyde
Kernel by Insyde
Kernel by Insyde
Kernel by Insyde
Kernel by Insyde
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise via arbitrary code execution at boot time, allowing persistent malware installation below the OS level.
Likely Case
Local privilege escalation or bootkit installation by attackers with physical access or administrative privileges.
If Mitigated
Limited impact if firmware is patched and secure boot is enabled, preventing unauthorized code execution.
🎯 Exploit Status
Requires ability to write to NVRAM variables, typically needing administrative or physical access. DXE phase exploitation is complex but powerful.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel 5.2: Version 05.29.44; Kernel 5.3: Version 05.38.44; Kernel 5.4: Version 05.46.44; Kernel 5.5: Version 05.54.44; Kernel 5.6: Version 05.61.44; Kernel 5.7: Version 05.70.44
Vendor Advisory: https://www.insyde.com/security-pledge/SA-2024015
Restart Required: Yes
Instructions:
1. Contact device manufacturer for firmware update. 2. Download appropriate firmware version for your kernel. 3. Apply firmware update using manufacturer's tools. 4. Reboot system to complete installation.
🔧 Temporary Workarounds
Restrict NVRAM Variable Access
allLimit write access to NVRAM variables through UEFI settings or security policies
Enable Secure Boot
allEnable UEFI Secure Boot to prevent unauthorized code execution during boot
🧯 If You Can't Patch
- Implement strict physical security controls to prevent unauthorized access
- Limit administrative privileges and monitor for suspicious NVRAM modifications
🔍 How to Verify
Check if Vulnerable:
Check firmware version in UEFI/BIOS settings or using manufacturer's system information toolsCheck Version:
Manufacturer-specific commands vary. Typically: wmic bios get smbiosbiosversion (Windows) or dmidecode -s bios-version (Linux)Verify Fix Applied:
Verify firmware version matches patched versions listed in vendor advisory📡 Detection & Monitoring
Log Indicators:
- Unexpected firmware modifications
- Suspicious NVRAM variable writes
- Boot integrity violations
Network Indicators:
- Not network exploitable - local vulnerability
SIEM Query:
Search for firmware update events or boot integrity alerts in system logs