CVE-2025-20096: Intel UEFI Privilege Escalation Flaw

CVE-2025-20096 Overview

CVE-2025-20096 is an improper input validation vulnerability affecting the UEFI firmware in some Intel Reference Platforms. This BIOS/UEFI vulnerability may allow a privileged local attacker to achieve escalation of privilege through data manipulation. The vulnerability requires local access, high complexity attack conditions, and active user interaction to exploit successfully.

Critical Impact

A privileged system software adversary may achieve privilege escalation through data manipulation, potentially compromising system integrity and availability.

Affected Products

• Intel Reference Platforms with vulnerable UEFI firmware
• Systems utilizing affected Intel UEFI firmware implementations

Discovery Timeline

• 2026-03-10 - CVE CVE-2025-20096 published to NVD
• 2026-03-11 - Last updated in NVD database

Technical Details for CVE-2025-20096

Vulnerability Analysis

This vulnerability stems from improper input validation (CWE-20) within the UEFI firmware implementation for certain Intel Reference Platforms. The flaw allows a system software adversary with privileged user access to perform data manipulation attacks under specific conditions. Successful exploitation requires local access to the vulnerable system, high attack complexity, the presence of specific attack requirements, and active user interaction.

The impact characteristics indicate that while confidentiality is not directly affected, the vulnerability poses significant risks to both integrity and availability. An attacker who successfully exploits this flaw can achieve high impact on system integrity and availability, with potential cascading effects on subsequent system components.

Root Cause

The root cause of CVE-2025-20096 is improper input validation within the UEFI firmware code. The firmware fails to adequately validate user-controlled input before processing, creating an opportunity for data manipulation. This input validation failure is classified under CWE-20 (Improper Input Validation), a common weakness where software does not validate or incorrectly validates input that affects the control flow or data flow of the program.

Attack Vector

The attack vector for this vulnerability is local access, meaning an attacker must have physical or local logical access to the target system. The exploitation path requires:

1. A privileged user account on the target system
2. High complexity attack conditions to be present
3. Specific attack requirements to be met
4. Active user interaction during the attack

The attacker would need to craft malicious input that bypasses validation checks in the UEFI firmware, potentially modifying firmware data or execution flow to achieve privilege escalation.

The vulnerability manifests through improper input validation in the UEFI firmware. Attackers with privileged local access may manipulate data passed to firmware components that fail to properly sanitize or validate the input. See the Intel Security Advisory SA-01393 for detailed technical information.

Detection Methods for CVE-2025-20096

Indicators of Compromise

• Unexpected UEFI firmware modifications or integrity check failures
• Anomalous privileged user activity targeting firmware interfaces
• System instability or availability issues following firmware interactions
• Unauthorized changes to boot configuration or secure boot settings

Detection Strategies

• Monitor firmware integrity using Trusted Platform Module (TPM) measurements and UEFI Secure Boot verification
• Implement privileged access monitoring for users with firmware-level access capabilities
• Deploy endpoint detection solutions capable of monitoring low-level system interactions
• Enable UEFI event logging and review for suspicious firmware access patterns

Monitoring Recommendations

• Establish baseline firmware measurements and alert on deviations
• Configure SIEM rules to correlate privileged user activity with firmware-related events
• Implement continuous monitoring of boot integrity and secure boot status
• Review system event logs for UEFI-related errors or anomalies regularly

How to Mitigate CVE-2025-20096

Immediate Actions Required

• Review the Intel Security Advisory SA-01393 for affected products and remediation guidance
• Identify all systems running vulnerable Intel Reference Platform UEFI firmware in your environment
• Apply firmware updates from Intel or your system vendor when available
• Restrict privileged user access to systems with vulnerable firmware
• Enable UEFI Secure Boot and verify its configuration

Patch Information

Intel has published security advisory Intel-SA-01393 addressing this vulnerability. System administrators should consult this advisory for specific firmware versions and patch availability. Contact your system vendor for applicable BIOS/UEFI updates that incorporate the security fix.

Workarounds

• Limit local privileged access to affected systems to trusted administrators only
• Enable and enforce UEFI Secure Boot to validate firmware integrity at boot time
• Implement physical security controls to restrict access to affected systems
• Monitor and audit all privileged user activity on vulnerable systems
• Consider isolating affected systems from critical network segments until patches are applied

# Verify Secure Boot status on Linux systems
mokutil --sb-state

# Check UEFI firmware version
dmidecode -t bios | grep -E "Version|Release"

# Review UEFI secure boot variables
efivar --list | grep SecureBoot