CVE-2025-2296 Overview
CVE-2025-2296 is an improper input validation vulnerability [CWE-20] in EDK2, the open-source UEFI firmware reference implementation maintained by the TianoCore project. The flaw resides in BIOS code paths that fail to properly validate input received through local interfaces. An authenticated local attacker with high privileges can supply crafted input that alters firmware control flow. Successful exploitation may lead to arbitrary command execution within the BIOS environment, affecting confidentiality, integrity, and availability of the affected system.
Critical Impact
Exploitation can alter firmware control flow and enable arbitrary command execution at the BIOS level, undermining platform trust below the operating system.
Affected Products
- TianoCore EDK2 reference firmware implementation
- Downstream UEFI BIOS builds derived from vulnerable EDK2 commits
- Platforms shipping firmware based on affected EDK2 modules
Discovery Timeline
- 2025-12-09 - CVE-2025-2296 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-2296
Vulnerability Analysis
The vulnerability is classified as Improper Input Validation [CWE-20] within EDK2 BIOS components. EDK2 modules process input from local sources, including runtime services callers, SMM handlers, and configuration interfaces. The affected code path accepts data without enforcing the bounds or type constraints expected by downstream logic. When an attacker supplies values outside the assumed range, the firmware proceeds with corrupted state. This deviation alters control flow within the BIOS execution context.
Because the flaw resides in firmware, exploitation operates beneath operating system security controls. Successful attacks can persist across reboots and evade endpoint defenses that rely on OS-level visibility. The vulnerability impacts confidentiality, integrity, and availability of the platform.
Root Cause
The root cause is missing or insufficient validation of input parameters consumed by an EDK2 BIOS routine. The function does not verify that incoming values conform to expected sizes, types, or ranges before using them in control decisions or memory operations. Detailed technical analysis is available in the GitHub Security Advisory.
Attack Vector
Exploitation requires local access to the system and elevated privileges sufficient to interact with the vulnerable firmware interface. An attacker with such access crafts malformed input that the BIOS routine processes without validation. The resulting control flow deviation can be steered toward arbitrary command execution within the firmware context. No public proof-of-concept exploit is available at this time, and the issue is not listed in the CISA Known Exploited Vulnerabilities catalog.
Detection Methods for CVE-2025-2296
Indicators of Compromise
- Unexpected firmware modifications or unsigned UEFI driver entries appearing after privileged local activity
- Anomalous SMM or runtime service invocations originating from non-administrative workflows
- Platform configuration changes that persist across operating system reinstallation
Detection Strategies
- Compare measured boot logs and TPM PCR values against known-good baselines to identify firmware drift
- Enroll endpoints in firmware attestation services that validate UEFI image integrity at boot
- Review vendor firmware update channels for advisories referencing the affected EDK2 modules
Monitoring Recommendations
- Collect UEFI Secure Boot and measured boot telemetry into a centralized log store for longitudinal analysis
- Alert on privileged local processes that invoke firmware configuration utilities outside maintenance windows
- Track BIOS version inventory across the fleet and flag systems running pre-patch EDK2 builds
How to Mitigate CVE-2025-2296
Immediate Actions Required
- Identify platforms running firmware derived from affected EDK2 revisions through asset inventory
- Apply vendor-supplied BIOS updates that incorporate the upstream EDK2 fix as soon as they are released
- Restrict local administrative access to reduce the population of users who meet the high-privilege precondition
Patch Information
The TianoCore project has published remediation details in the EDK2 GitHub Security Advisory GHSA-6pp6-cm5h-86g5. Downstream OEMs must integrate the corrected EDK2 source into their firmware builds and distribute updated BIOS images to affected platforms. Coordinate with hardware vendors to confirm patched firmware versions for each model.
Workarounds
- Enforce UEFI Secure Boot and BIOS administrator passwords to limit who can interact with firmware interfaces
- Enable measured boot and remote attestation to detect tampering until firmware updates are applied
- Apply principle of least privilege on managed endpoints to reduce the number of accounts capable of triggering the local attack path
# Configuration example
# Verify current UEFI firmware version on Linux to confirm patch status
sudo dmidecode -s bios-version
sudo dmidecode -s bios-release-date
# Confirm Secure Boot status
mokutil --sb-state
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
