CVE-2024-36877: MSI Motherboard Privilege Escalation Flaw

CVE-2024-36877 Overview

Micro-Star International (MSI) Z-series (Z590, Z490, and Z790) and B-series (B760, B560, B660, and B460) motherboards with firmware versions 7D25v14, 7D25v17 to 7D25v19, and 7D25v1A to 7D25v1H have been found to contain a write-what-where condition in the SW handler for SMI 0xE3. This condition can lead to severe security issues, affecting motherboards with Intel 300, Intel 400, Intel 500, Intel 600, Intel 700, AMD 300, AMD 400, AMD 500, AMD 600, and AMD 700 chipsets.

Critical Impact
This vulnerability can lead to local elevation of privilege and potentially full system compromise due to the write-what-where condition.

Affected Products

MSI Z590
MSI Z490
MSI Z790

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to Not Available
Not Available - CVE CVE-2024-36877 assigned
Not Available - Vendor releases security patch
2024-08-12 - CVE CVE-2024-36877 published to NVD
2025-03-13 - Last updated in NVD database

Technical Details for CVE-2024-36877

Vulnerability Analysis

The vulnerability arises from a mishandling of the SMI 0xE3 in MSI's firmware, which allows an attacker to execute arbitrary writes in memory locations. The flaw exists due to an inadequate validation mechanism in the SW handler, leading to potential escalation of privileges on affected systems.

Root Cause

The root cause of this issue is a lack of proper input validation in the SW handler for SMI 0xE3, allowing for unauthorized memory manipulation.

Attack Vector

Local

// Example exploitation code (sanitized)
void exploit() {
    trigger_SMI(0xE3);
    write_memory(target_address, malicious_payload);
}

Detection Methods for CVE-2024-36877

Indicators of Compromise

Unusual SMI (System Management Interrupt) call patterns
Unexpected memory write operations
Altered firmware version identifiers

Detection Strategies

Implement monitoring for SMI calls and verify the integrity of the firmware using known good hashes. Anomalous patterns in SMM (System Management Mode) should be flagged.

Monitoring Recommendations

Regularly audit SMM activity and integrate automated checks for firmware integrity. Leverage endpoint detection capabilities to identify unauthorized memory writes.

How to Mitigate CVE-2024-36877

Immediate Actions Required

Update to the latest firmware versions provided by MSI
Monitor systems for signs of exploitation
Implement least privilege for systems that interact with motherboard firmware

Patch Information

Please visit the MSI advisory page for the latest patch details corresponding to specific motherboard models.

Workarounds

Minimize exposure to potential exploits by disabling unnecessary system management mode functionalities where applicable and ensuring secure boot configurations.

bash

# Configuration example
echo "Disabling unnecessary SMI handling"
set_smi_handling disable