CVE-2024-36877 in Z590
Summary
by MITRE • 08/12/2024
Micro-Star International Z-series motherboards (Z590, Z490, and Z790) and B-series motherboards (B760, B560, B660, and B460) with firmware 7D25v14, 7D25v17 to 7D25v19, and 7D25v1A to 7D25v1H was discovered to contain a write-what-where condition in the in the SW handler for SMI 0xE3.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/15/2025
The vulnerability identified as CVE-2024-36877 represents a critical security flaw affecting Micro-Star International motherboards across multiple chipset series including Z590, Z490, Z790, B760, B560, B660, and B460 models. This issue manifests within the firmware implementation of these motherboards, specifically in the Software Handler for System Management Interrupt (SMI) number 0xE3. The affected firmware versions span from 7D25v14 through 7D25v19 and 7D25v1A to 7D25v1H, indicating a widespread impact across several motherboard generations. The vulnerability stems from improper input validation and memory management within the SMI handler, creating a write-what-where condition that allows malicious actors to potentially execute arbitrary code at the System Management Mode (SMM) privilege level.
The technical flaw constitutes a classic buffer overflow condition within the SMI handler mechanism, which operates at the highest privilege level in x86 systems. When an SMI interrupt is triggered with code 0xE3, the firmware fails to properly validate or sanitize the input data being written to memory locations. This write-what-where condition enables an attacker to specify both the memory address where data should be written and the value to be written, effectively allowing arbitrary memory modification. The vulnerability is particularly dangerous because SMM operates with the highest privilege level, meaning any code executed within this realm can bypass all standard operating system security mechanisms including kernel protections, user-mode address space layout randomization, and memory protection features. This represents a fundamental breach of the system's security model, as demonstrated by the CWE-787 weakness classification for out-of-bounds write vulnerabilities.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete system compromise and potential persistence mechanisms. Attackers who successfully exploit this condition could gain root-level access to the system, allowing them to modify critical system components, install backdoors, or extract sensitive data without detection. The vulnerability's exploitation potential is heightened by the fact that SMI handlers are often invoked during system boot processes or hardware initialization, providing attackers with opportunities to establish persistent access. Additionally, since SMM operates outside the normal operating system execution context, traditional security monitoring tools and operating system-based protections become ineffective against attacks leveraging this vulnerability. The ATT&CK framework categorizes this as a privilege escalation technique under T1068, where attackers leverage system management mode to gain unauthorized access to system resources.
Mitigation strategies for CVE-2024-36877 require immediate firmware updates from Micro-Star International, as the vulnerability exists at the firmware level and cannot be resolved through software patches alone. System administrators should prioritize updating all affected motherboard firmware to the latest versions provided by the manufacturer, ensuring that the updated firmware properly validates all input data within the SMI 0xE3 handler. Hardware-level protections should also be considered, including disabling SMI interrupts when possible and implementing firmware integrity monitoring solutions that can detect unauthorized modifications to the SMM code. Organizations should conduct thorough vulnerability assessments to identify all affected systems and implement network segmentation to limit potential attack vectors. The vulnerability's nature makes it particularly challenging to detect through conventional means, as SMM operations occur outside normal system monitoring scopes, necessitating specialized forensic tools and techniques for detection. Furthermore, due to the critical nature of SMM-based vulnerabilities, organizations should consider implementing hardware security modules or trusted platform modules to provide additional layers of system integrity protection.