CVE-2019-14563
📋 TL;DR
CVE-2019-14563 is an integer truncation vulnerability in EDK II (UEFI firmware) that allows authenticated local users to potentially escalate privileges. This affects systems using vulnerable EDK II implementations, primarily impacting servers and workstations with affected UEFI firmware. The vulnerability requires local access and authentication to exploit.
💻 Affected Systems
- EDK II (UEFI firmware implementations)
- Systems using Tianocore EDK II
📦 What is this software?
Edk2 by Tianocore
⚠️ Risk & Real-World Impact
Worst Case
An authenticated attacker could gain SYSTEM/root privileges, install persistent malware in firmware, bypass security controls, and maintain persistence across OS reinstalls.
Likely Case
Privilege escalation from standard user to administrator/root on affected systems, allowing installation of additional malware or access to sensitive data.
If Mitigated
With proper access controls and least privilege principles, impact is limited to authorized users only, reducing overall risk.
🎯 Exploit Status
Requires local authenticated access and knowledge of firmware exploitation techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: EDK II commit 0b544b3424c9 or later
Vendor Advisory: https://bugzilla.tianocore.org/show_bug.cgi?id=2001
Restart Required: Yes
Instructions:
1. Check with system/firmware vendor for BIOS/UEFI firmware updates. 2. Apply firmware update from vendor. 3. Reboot system to activate new firmware.
🔧 Temporary Workarounds
Restrict physical and local access
allLimit physical access to systems and enforce strict authentication controls
Implement least privilege
allEnsure users only have necessary privileges to reduce impact of privilege escalation
🧯 If You Can't Patch
- Isolate affected systems in secure network segments
- Implement strict access controls and monitoring for privileged accounts
🔍 How to Verify
Check if Vulnerable:
Check system firmware version against vendor advisories or use: dmidecode -t bios (Linux) or wmic bios get smbiosbiosversion (Windows)Check Version:
Linux: dmidecode -t bios | grep Version; Windows: wmic bios get smbiosbiosversionVerify Fix Applied:
Verify firmware version has been updated to vendor-provided patched version📡 Detection & Monitoring
Log Indicators:
- Unusual firmware access attempts
- Privilege escalation events
- Unexpected system reboots for firmware updates
Network Indicators:
- N/A - local access required
SIEM Query:
EventID=6005 (System startup) correlated with firmware update events or privilege escalation alerts