CVE-2024-42446
📋 TL;DR
This CVE describes a Time-of-check Time-of-use (TOCTOU) race condition vulnerability in AMI's APTIOV BIOS firmware. An attacker with local access can exploit this to execute arbitrary code at the BIOS level, potentially compromising the entire system. This affects systems using vulnerable versions of AMI's APTIOV BIOS firmware.
💻 Affected Systems
- Systems using AMI APTIOV BIOS firmware
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with persistent BIOS-level malware that survives OS reinstallation and disk replacement, enabling long-term espionage or destruction.
Likely Case
Local privilege escalation allowing attackers to gain kernel-level access, install rootkits, bypass security controls, and maintain persistence.
If Mitigated
Limited impact if systems have secure boot enabled, BIOS write protection active, and physical access controls preventing unauthorized local access.
🎯 Exploit Status
Exploitation requires local access and precise timing to win the race condition. BIOS-level vulnerabilities typically require sophisticated exploitation techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to AMI security advisory for specific patched versions
Vendor Advisory: https://go.ami.com/hubfs/Security%20Advisories/2025/AMI-SA-2025004.pdf
Restart Required: Yes
Instructions:
1. Check AMI security advisory for affected systems. 2. Contact your hardware vendor/OEM for BIOS/UEFI firmware updates. 3. Download appropriate BIOS update from vendor. 4. Apply BIOS update following vendor instructions. 5. Reboot system to complete update.
🔧 Temporary Workarounds
Enable Secure Boot
allSecure Boot helps prevent unauthorized code execution at boot time by verifying digital signatures
Enable BIOS Write Protection
allConfigure BIOS settings to prevent unauthorized modifications to BIOS firmware
🧯 If You Can't Patch
- Restrict physical access to systems - implement strict physical security controls
- Implement least privilege access controls and monitor for suspicious local privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check BIOS version against vendor's vulnerability list. Use systeminfo command on Windows or dmidecode on Linux to identify BIOS vendor and version.Check Version:
Windows: wmic bios get smbiosbiosversion
Linux: sudo dmidecode -s bios-versionVerify Fix Applied:
Verify BIOS version has been updated to patched version specified in vendor advisory. Check that Secure Boot is enabled and functioning.📡 Detection & Monitoring
Log Indicators:
- Unexpected BIOS/UEFI firmware modification events
- Failed Secure Boot validations
- Suspicious local privilege escalation patterns
Network Indicators:
- No network-based indicators as this is a local vulnerability
SIEM Query:
EventID=12 OR EventID=13 (System events for boot/startup) combined with privilege escalation patterns