Endpoint Security,
Hardware / Chip-level Security
UEFI Vulnerability Poses Risk of Covert Compromise
A recently discovered vulnerability allows hackers to bypass Secure Boot protections, potentially impacting numerous Windows laptops and servers. While this attack method has its limitations—requiring both administrative and physical access to a device—Microsoft has released a patch to mitigate the risk.
This issue underscores the escalating series of vulnerabilities tied to Unified Extensible Firmware Interface (UEFI) firmware, which is critical in the hardware initialization process during system startup. Since UEFI operates prior to the activation of the operating system, it remains a key target for cyber adversaries (see: Researchers Identify Significant UEFI Secure Boot Bypass Vulnerability).
Researchers from Binarly reported discovering a module for boot firmware on VirusTotal last November. Developed by a vendor specializing in rugged displays, the module contains a flaw identified as CVE-2025-3052, which is attributed to a memory corruption vulnerability within the UEFI framework. Armed with a Microsoft third-party certificate, this module allows attackers to overwrite critical variables necessary for enforcing Secure Boot.
Specifically, Binarly researchers noted that the module utilizes the UEFI IhisiParamBuffer variable without proper validation, permitting an attacker to direct it to any arbitrary memory address. This oversight effectively provides an arbitrary memory write capability, granting potential adversaries significant control.
The IhisiParamBuffer variable is stored in non-volatile RAM, known for retaining essential data across boots. Notably, vulnerabilities associated with NVRAM have been a consistent issue within cybersecurity, as evidenced by leaked documents from WikiLeaks that revealed CIA techniques targeting NVRAM to take over system boot processes (see: Breach Roundup: CIA Hacking Tool Leaker Sentenced to 40 Years).
While certain UEFI distributions are insulated from this vulnerability by designating the IhisiParamBuffer as read-only, the majority of systems remain susceptible. Additional analysis disclosed that the module has likely been circulating online since October 2022.
When the exploit is executed successfully, systems may still function as though Secure Boot is active. Upon reporting the flaw to Microsoft, it was discovered that an additional 13 firmware modules shared this vulnerability. Consequently, Microsoft revoked the associated certificates for all affected modules in the most recent Patch Tuesday updates.
