CVE-2024-37989: Windows 10 1507 Secure Boot Bypass Flaw

CVE-2024-37989 Overview

CVE-2024-37989 is a Secure Boot security feature bypass vulnerability affecting Microsoft Windows and Windows Server platforms. The flaw is tracked under [CWE-130] (improper handling of length parameter inconsistency) and was published to the National Vulnerability Database on July 9, 2024. An adjacent-network attacker who can influence the boot process can bypass Secure Boot integrity checks. Successful exploitation impacts confidentiality, integrity, and availability of the affected host. Microsoft has published an official advisory and shipped remediation through Windows Update.

Critical Impact
A successful Secure Boot bypass allows unsigned or malicious boot components to execute before the operating system loads, undermining the root of trust for the entire Windows platform.

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 2022 23H2

Discovery Timeline

2024-07-09 - CVE-2024-37989 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-37989

Vulnerability Analysis

CVE-2024-37989 is classified as a Secure Boot bypass rooted in improper handling of a length parameter inconsistency ([CWE-130]). Secure Boot is the Unified Extensible Firmware Interface (UEFI) feature that enforces cryptographic verification of every module loaded during the boot chain. When length handling is incorrect, a specially crafted boot artifact can be accepted by the validation logic even though it does not meet the expected trust criteria.

Microsoft categorizes the issue as a security feature bypass rather than remote code execution. The attack vector is adjacent, meaning the attacker must be positioned on the same logical network or otherwise adjacent to the target. User interaction is required, which typically implies a reboot or a triggered boot operation on the victim system.

Root Cause

The root cause is improper validation of length fields during Secure Boot processing. The validator does not consistently reconcile declared lengths with actual buffer or object sizes, allowing crafted content to pass integrity gating. This category of defect defeats the intended cryptographic guarantee that only trusted code executes before the Windows kernel initializes.

Attack Vector

An attacker with adjacent-network access and the ability to influence a boot artifact on the target can trigger the bypass during the next reboot. Once Secure Boot no longer blocks the malicious component, an attacker can persist a bootkit, disable subsequent OS-level defenses, or tamper with the kernel before endpoint security agents start. The Microsoft advisory should be consulted for exact prerequisites; no public proof-of-concept exploit is listed in the enriched data.

No verified exploit code is publicly available for this CVE. See the Microsoft CVE-2024-37989 Advisory for technical details.

Detection Methods for CVE-2024-37989

Indicators of Compromise

Unexpected modifications to UEFI boot variables, boot order entries, or the EFI System Partition (ESP) contents.
New or altered .efi binaries under \EFI\Microsoft\Boot\ that are not signed by a trusted Microsoft certificate.
Secure Boot state reported as disabled by Confirm-SecureBootUEFI on a host where policy requires it enabled.
Measured Boot / TPM PCR values (PCR[0], PCR[2], PCR[4], PCR[7]) that diverge from a known-good baseline.

Detection Strategies

Collect and compare Windows Measured Boot logs and TPM attestation data against a trusted baseline for each hardware model.
Query HKLM\SYSTEM\CurrentControlSet\Control\SecureBoot\State and event ID 1035 in the Microsoft-Windows-Kernel-Boot log to identify Secure Boot state transitions.
Correlate boot configuration changes (bcdedit modifications, ESP writes) with the user and process context that generated them.

Monitoring Recommendations

Enable Device Health Attestation or an equivalent remote attestation service to detect hosts booting with drift from the expected chain.
Ingest Windows boot and firmware events into a SIEM and alert on Secure Boot disablement, revoked certificate use, or DBX update failures.
Track patch compliance for KB articles associated with CVE-2024-37989 across all Windows 10, Windows 11, and Windows Server assets.

How to Mitigate CVE-2024-37989

Immediate Actions Required

Deploy the Microsoft security update referenced in the Microsoft CVE-2024-37989 Advisory to all affected Windows and Windows Server systems.
Verify Secure Boot is enabled on every managed endpoint using Confirm-SecureBootUEFI and remediate any host reporting False.
Apply relevant Secure Boot DBX (forbidden signature database) updates so that revoked bootloaders cannot be loaded.
Prioritize domain controllers, jump hosts, and servers exposed to adjacent networks such as management VLANs.

Patch Information

Microsoft has released cumulative updates that address CVE-2024-37989 across all supported Windows 10, Windows 11, and Windows Server branches listed in the advisory. Refer to the Microsoft CVE-2024-37989 Advisory for the specific KB numbers per product version and for any required servicing stack updates.

Workarounds

Restrict physical and adjacent-network access to systems that cannot be patched immediately, including out-of-band management interfaces.
Require BitLocker with TPM+PIN so that boot-chain tampering forces recovery-key entry and is visible to operators.
Enforce firmware and UEFI administrator passwords to prevent unauthorized changes to Secure Boot policy.

bash

# Verify Secure Boot state and current UEFI policy on Windows
Confirm-SecureBootUEFI
Get-SecureBootPolicy

# Confirm the CVE-2024-37989 update is installed (replace KB with the ID from the advisory)
Get-HotFix | Where-Object { $_.HotFixID -eq 'KBXXXXXXX' }