CVE-2020-12961
📋 TL;DR
This vulnerability in AMD's Platform Security Processor (PSP) allows attackers to manipulate privileged registers on the System Management Network, potentially bypassing SPI ROM protections. This affects systems with AMD processors containing the vulnerable PSP firmware. Attackers could gain elevated privileges or compromise system integrity.
💻 Affected Systems
- AMD Ryzen processors
- AMD EPYC processors
- AMD Athlon processors with Radeon Vega Graphics
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to bypass hardware security protections, install persistent malware in firmware, or gain full control over the system.
Likely Case
Local privilege escalation allowing attackers to gain higher privileges on already compromised systems or bypass security controls.
If Mitigated
Limited impact if systems are fully patched and have proper security controls like secure boot enabled.
🎯 Exploit Status
Exploitation requires local access and deep knowledge of AMD PSP architecture. No public exploits have been reported.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: PSP firmware updates provided by AMD and system manufacturers
Vendor Advisory: https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1021
Restart Required: Yes
Instructions:
1. Check with your system/motherboard manufacturer for BIOS/UEFI updates. 2. Download the latest BIOS/UEFI firmware. 3. Follow manufacturer instructions to update firmware. 4. Reboot system after update.
🔧 Temporary Workarounds
Enable Secure Boot
allEnable Secure Boot in BIOS/UEFI settings to help protect against firmware-level attacks
Restrict Physical Access
allLimit physical access to systems as exploitation requires local access
🧯 If You Can't Patch
- Isolate affected systems from critical networks
- Implement strict access controls and monitoring for systems with vulnerable firmware
🔍 How to Verify
Check if Vulnerable:
Check BIOS/UEFI version against manufacturer's patched versions. Use 'sudo dmidecode -t bios' on Linux or check System Information on Windows.Check Version:
Linux: sudo dmidecode -t bios | grep Version; Windows: wmic bios get smbiosbiosversionVerify Fix Applied:
Verify BIOS/UEFI version matches or exceeds manufacturer's recommended patched version.📡 Detection & Monitoring
Log Indicators:
- Unexpected BIOS/UEFI modifications
- Failed firmware update attempts
- System management network anomalies
Network Indicators:
- Unusual outbound connections from management interfaces
SIEM Query:
source="bios_logs" AND (event_type="firmware_modification" OR event_type="privileged_register_access")