CVE-2023-34440
📋 TL;DR
This UEFI firmware vulnerability in certain Intel processors allows a privileged attacker with local access to potentially escalate privileges by exploiting improper input validation. It affects systems running vulnerable Intel processor firmware. The attacker must already have privileged access to the system.
💻 Affected Systems
- Intel processors with vulnerable UEFI firmware
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where attacker gains highest privilege level (ring -2/SMM) and can install persistent firmware-level malware that survives OS reinstallation.
Likely Case
Privilege escalation from administrator/root to firmware-level access, enabling persistence mechanisms and bypassing OS security controls.
If Mitigated
Limited impact if proper access controls prevent unauthorized privileged access and firmware integrity protections are enabled.
🎯 Exploit Status
Requires privileged local access and knowledge of UEFI exploitation techniques. No public exploit code available as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Updated UEFI firmware from system/device manufacturer
Vendor Advisory: https://intel.com/content/www/us/en/security-center/advisory/intel-sa-01139.html
Restart Required: Yes
Instructions:
1. Check system/motherboard manufacturer website for BIOS/UEFI firmware updates. 2. Download appropriate firmware update for your specific hardware model. 3. Follow manufacturer's firmware update instructions carefully (usually involves bootable USB or Windows/Linux updater). 4. Reboot system to apply firmware update.
🔧 Temporary Workarounds
Restrict privileged access
allLimit administrative/root access to essential personnel only to reduce attack surface
Enable firmware integrity protections
allEnable Secure Boot and Intel Boot Guard if supported by hardware
🧯 If You Can't Patch
- Implement strict access controls and monitoring for privileged accounts
- Consider hardware replacement if critical systems cannot be updated
🔍 How to Verify
Check if Vulnerable:
Check system BIOS/UEFI version against manufacturer's patched versions. Use 'sudo dmidecode -t bios' on Linux or 'wmic bios get smbiosbiosversion' on Windows.Check Version:
Linux: sudo dmidecode -t bios | grep Version; Windows: wmic bios get smbiosbiosversionVerify Fix Applied:
Verify BIOS/UEFI version matches patched version from manufacturer after update. Check that Secure Boot is enabled if supported.📡 Detection & Monitoring
Log Indicators:
- Unexpected BIOS/UEFI configuration changes
- Failed firmware update attempts
- Privileged account anomalies
Network Indicators:
- None - local exploitation only
SIEM Query:
Search for: (EventID=6008 OR 'unexpected shutdown') AND (process='firmware' OR 'bios update') OR privileged account access outside normal patterns