Gigabyte Motherboard UEFI Vulnerabilities Expose Systems to Persistent Bootkit Malware

Security researchers have identified critical vulnerabilities in Gigabyte motherboards that allow attackers to bypass Secure Boot and deploy persistent UEFI malware. The flaws affect over 240 models, including popular Z690, B550, and X570 series, enabling attackers to execute code in System Management Mode (SMM) – a privileged CPU environment isolated from the operating system¹.

Executive Summary for Security Leaders

The vulnerabilities (CVE-2025-7026 to CVE-2025-7029) enable attackers to:

Bypass Secure Boot protections
Maintain persistence across OS reinstalls
Execute code in SMM (Ring -2)
Write to protected SMRAM memory regions

Gigabyte has released firmware updates, but many end-of-life devices remain unpatched. The CVSS scores range from 8.2 to 8.8, reflecting the high risk of firmware-level compromise².

Technical Analysis of UEFI Vulnerabilities

The vulnerabilities stem from improper validation in System Management Interrupt (SMI) handlers, which are privileged firmware components that handle low-level system events. Four specific CVEs have been identified:

CVE	Vulnerability Type	Affected Component
CVE-2025-7029	SMM privilege escalation	OverClockSmiHandler
CVE-2025-7028	Arbitrary SMRAM writes	SmiFlash
CVE-2025-7027	SMM privilege escalation	NVRAM manipulation
CVE-2025-7026	Arbitrary SMRAM writes	CommandRcx0

These vulnerabilities allow attackers to corrupt SMRAM or inject malicious code that persists across operating system reinstalls. The flaws are particularly dangerous because they operate below the OS level, making detection difficult³.

Mitigation and Detection Strategies

Organizations using affected Gigabyte motherboards should implement the following measures:

Update firmware immediately via Gigabyte’s security portal
Disable “APP Center Download & Install” in BIOS settings
Block known malicious URLs used by Gigabyte’s update service
Use Binarly’s Risk Hunt scanner for detection
Monitor for unexpected SMM activity

Security teams should pay particular attention to firmware-level anomalies, as traditional endpoint detection solutions may not catch SMM-based attacks⁴.

Historical Context and Related Threats

This isn’t the first time Gigabyte has faced firmware security issues. In 2023, researchers discovered that Gigabyte firmware embedded a Windows executable (GigabyteUpdateService.exe) that insecurely downloaded payloads⁵. The current vulnerabilities follow a pattern of firmware supply chain risks that have affected multiple vendors over the years.

The discovery comes amid growing concerns about UEFI malware, particularly after the emergence of the BlackLotus bootkit in 2023, which became the first malware capable of bypassing Secure Boot on Windows 11 systems¹.

Conclusion

These Gigabyte UEFI vulnerabilities represent a significant threat to system integrity, particularly in enterprise environments where firmware security is often overlooked. The ability to maintain persistence at the firmware level makes these flaws particularly dangerous for high-security environments.

Security teams should prioritize firmware updates and consider implementing additional monitoring for SMM activity. As firmware attacks become more sophisticated, organizations must expand their security monitoring beyond the operating system level to include firmware integrity checks.