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Infecting the Boot to Own the Kernel

Alejandro VazquezMaria San Jose

Demonstrates how boot-level vulnerabilities and flawed UEFI implementations bypass Secure Boot to execute persistent kernel-level bootkits.

Summary

The Critical Role of Secure Boot

UEFI Secure Boot is designed to establish a cryptographic chain of trust from the hardware bootloader through the operating system kernel, blocking unsigned code execution.

Exploiting Vulnerabilities in UEFI Bootloaders

Alejandro Vazquez and Maria San Jose analyze implementation flaws in third-party signed UEFI binaries and bootloader components that allow attackers to bypass signature validation.

Installing Persistent Ring-0 Bootkits

Manipulating boot configuration parameters and exploiting memory corruption flaws during early boot allows attackers to patch kernel memory, disable Driver Signature Enforcement, and achieve persistent ring-0 execution.

Defensive Architecture and Firmware Revocation

Mitigating bootkits requires maintaining updated Secure Boot Forbidden Signature Databases (DBX), deploying Hardware Root of Trust, and enforcing firmware integrity monitoring.

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