CVE-2021-0159
📋 TL;DR
This vulnerability allows a privileged user with local access to potentially escalate privileges through improper input validation in the BIOS authenticated code module of certain Intel processors. It affects systems with specific Intel processors that have not received BIOS/UEFI firmware updates. The attack requires local access and elevated privileges to exploit.
💻 Affected Systems
- Intel Processors with specific BIOS authenticated code modules
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
A privileged attacker could gain higher-level system privileges, potentially compromising the entire system, accessing sensitive data, or installing persistent malware at the firmware level.
Likely Case
An attacker with existing local administrative access could further escalate privileges to gain complete control over the system, bypassing security controls.
If Mitigated
With proper BIOS/UEFI firmware updates applied, the vulnerability is eliminated. Systems with strict privilege separation and minimal local administrative users face reduced risk.
🎯 Exploit Status
Exploitation requires local access, privileged credentials, and detailed knowledge of the BIOS authenticated code module. No public exploit code has been reported.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: BIOS/UEFI firmware updates provided by system manufacturers
Vendor Advisory: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00601.html
Restart Required: Yes
Instructions:
1. Check your system manufacturer's website for BIOS/UEFI firmware updates. 2. Download the appropriate firmware update for your specific system model. 3. Follow the manufacturer's instructions to apply the firmware update. 4. Reboot the system to complete the update process.
🔧 Temporary Workarounds
Restrict Local Administrative Access
allLimit the number of users with local administrative privileges to reduce the attack surface.
Implement Least Privilege
allEnsure users and applications run with only the minimum necessary privileges.
🧯 If You Can't Patch
- Isolate affected systems from critical networks and sensitive data
- Implement strict monitoring and logging of privileged user activities
🔍 How to Verify
Check if Vulnerable:
Check your system's BIOS/UEFI firmware version against the patched versions listed by your system manufacturer. Use manufacturer-specific tools or BIOS settings to view firmware version.Check Version:
System-specific: For Windows: wmic bios get smbiosbiosversion; For Linux: sudo dmidecode -s bios-versionVerify Fix Applied:
Verify that the BIOS/UEFI firmware version matches or exceeds the patched version specified by your system manufacturer.📡 Detection & Monitoring
Log Indicators:
- Unusual BIOS/UEFI firmware modification attempts
- Privilege escalation attempts from known administrative accounts
- Unexpected system reboots or firmware update activities
Network Indicators:
- Not applicable - local access vulnerability
SIEM Query:
Search for events related to BIOS/UEFI firmware modifications, unexpected privilege escalation, or suspicious local administrative activities