CVE-2024-37988 Overview
CVE-2024-37988 is a Secure Boot security feature bypass vulnerability affecting multiple versions of Microsoft Windows and Windows Server. The flaw stems from improper handling of length parameters [CWE-130] within the Secure Boot boot chain. An attacker on an adjacent network can leverage this weakness to bypass Unified Extensible Firmware Interface (UEFI) Secure Boot integrity checks. Successful exploitation requires user interaction and can lead to compromise of confidentiality, integrity, and availability of the affected system.
Critical Impact
Attackers who bypass Secure Boot can load unsigned or malicious code during the boot process, undermining platform trust and enabling persistent, pre-OS implants such as bootkits.
Affected Products
- Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
- Microsoft Windows 11 (versions 21H2, 22H2, 23H2)
- Microsoft Windows Server 2012, 2016, 2019, 2022, and Server 23H2
Discovery Timeline
- 2024-07-09 - CVE-2024-37988 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-37988
Vulnerability Analysis
CVE-2024-37988 is a Secure Boot bypass rooted in improper handling of length parameters during boot-time validation. Secure Boot enforces cryptographic verification of firmware and boot loaders using Platform Keys and the UEFI signature database. When a length field is mishandled, verification logic can be tricked into accepting untrusted content as legitimate. Attackers can use this behavior to load modified boot components that would normally fail Secure Boot checks.
Exploitation requires adjacent network access and user interaction. The CWE-130 classification indicates that the flaw resides in how the affected component parses or trusts a length value used during boot validation. Because the compromise occurs before the operating system loads, malicious code introduced through this path can survive reboots and evade in-OS defenses.
Root Cause
The underlying weakness is improper handling of a length parameter [CWE-130] in a Secure Boot component. Miscalculated or unchecked length values allow attacker-controlled data to alter validation outcomes. Microsoft has not published low-level implementation details in the public advisory.
Attack Vector
The attack vector is adjacent network (AV:A) with low complexity, no privileges required, and user interaction required. An attacker positioned on the same logical network segment must convince a user to perform an action that triggers the vulnerable boot-path handling. Successful exploitation bypasses Secure Boot and can lead to persistent pre-boot code execution.
No verified public proof-of-concept exploit is available for CVE-2024-37988. Refer to the Microsoft CVE-2024-37988 Advisory for vendor-supplied technical details.
Detection Methods for CVE-2024-37988
Indicators of Compromise
- Unexpected changes to the UEFI signature database (db), forbidden signature database (dbx), Key Exchange Key (KEK), or Platform Key (PK).
- Boot Configuration Data (BCD) modifications or new, unsigned entries appearing in the EFI System Partition.
- Secure Boot state reporting as disabled or misconfigured on endpoints that were previously compliant.
- Presence of unknown .efi binaries in \EFI\Microsoft\Boot\ or \EFI\Boot\.
Detection Strategies
- Monitor Windows Event Log for TPM and Measured Boot events, including Event IDs 1035 and 1036, that indicate boot integrity anomalies.
- Compare TPM Platform Configuration Register (PCR) values against known-good baselines to identify boot component tampering.
- Use firmware attestation and Device Health Attestation (DHA) to flag endpoints whose Secure Boot chain diverges from policy.
- Alert on administrative changes to Secure Boot variables via UEFI runtime services.
Monitoring Recommendations
- Enable and centralize Measured Boot logs from endpoints to a SIEM for continuous evaluation.
- Track patch state across all affected Windows and Windows Server SKUs to identify unpatched systems.
- Correlate adjacent-network activity such as rogue DHCP, PXE, or Wi-Fi access points with boot-time anomalies.
How to Mitigate CVE-2024-37988
Immediate Actions Required
- Apply the Microsoft security updates referenced in the Microsoft CVE-2024-37988 Advisory to all affected Windows and Windows Server versions.
- Verify Secure Boot is enabled in firmware and enforced by policy on every managed endpoint.
- Restrict physical and adjacent-network access to sensitive systems, particularly on unmanaged or guest network segments.
- Update the UEFI forbidden signature database (dbx) to revoke known-vulnerable boot components as Microsoft publishes revocations.
Patch Information
Microsoft addresses CVE-2024-37988 through the security updates listed in the vendor advisory. Because Secure Boot bypass fixes often require coordinated updates to both the operating system and the UEFI revocation list, administrators should confirm that both the cumulative Windows update and any dbx revocation update have been applied. See the Microsoft CVE-2024-37988 Advisory for the complete list of KB articles per Windows build.
Workarounds
- Enforce BitLocker with TPM and PIN so that boot tampering triggers recovery-mode prompts and blocks silent compromise.
- Require Device Health Attestation for access to sensitive resources, denying non-compliant endpoints via Conditional Access.
- Segment networks to prevent untrusted devices from reaching high-value systems over adjacent Layer 2 or Layer 3 links.
# Verify Secure Boot state and Windows patch level on affected systems
Confirm-SecureBootUEFI
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Get-Tpm
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
