CVE-2021-0156
📋 TL;DR
This vulnerability allows an authenticated attacker with local access to improperly validate input in Intel processor firmware, potentially enabling privilege escalation. It affects specific Intel processors with vulnerable firmware versions. The attacker must already have authenticated access to the system.
💻 Affected Systems
- Intel Processors with specific firmware versions
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
An authenticated attacker gains full system control, potentially compromising the entire system and accessing sensitive data or installing persistent malware.
Likely Case
An authenticated user with malicious intent escalates privileges to perform unauthorized actions, install software, or access restricted data on the local system.
If Mitigated
With proper access controls and monitoring, impact is limited to the local system where the attacker already has authenticated access.
🎯 Exploit Status
Requires authenticated local access and knowledge of specific firmware exploitation techniques. No public exploit code has been disclosed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware updates provided by Intel and system manufacturers
Vendor Advisory: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00527.html
Restart Required: Yes
Instructions:
1. Check Intel advisory for affected processor models. 2. Contact system manufacturer for firmware updates. 3. Apply firmware updates following manufacturer instructions. 4. Reboot system to activate new firmware.
🔧 Temporary Workarounds
Restrict local access
allLimit authenticated local access to only trusted users and implement strict access controls
Monitor privileged operations
allImplement monitoring for unusual privilege escalation attempts
🧯 If You Can't Patch
- Implement strict access controls to limit authenticated local access
- Monitor systems for unusual privilege escalation activities and maintain detailed audit logs
🔍 How to Verify
Check if Vulnerable:
Check processor model and firmware version against Intel advisory. Use manufacturer tools to check current firmware version.Check Version:
Manufacturer-specific commands vary. For Linux: 'sudo dmidecode -t bios' or 'sudo lshw -class firmware'. For Windows: 'wmic bios get smbiosbiosversion'Verify Fix Applied:
Verify firmware version has been updated to patched version using manufacturer tools or BIOS/UEFI interface.📡 Detection & Monitoring
Log Indicators:
- Unusual privilege escalation events
- Firmware modification attempts
- Unexpected system reboots or firmware updates
Network Indicators:
- Not applicable - local access vulnerability
SIEM Query:
Search for events indicating firmware modifications, unexpected privilege changes, or authentication from unusual locations followed by privilege escalation