A Stealth Security Hardening Method Based on SSD Firmware Function Extension

Xiao Yu, Zhao Li, Xu Qiao, Yu-an Tan, Yuanzhang Li, Li Zhang

Abstract: In recent years, issues related to information security have received increasing attention. Expanding the security-related functionality of SSD firmware can provide an additional method for implementing security features in the host system while taking advantage of the excellent performance of the SSD controller. This paper proposes a stealth security hardening method based on SSD Firmware Function Extension. By reverse engineering the firmware program and inserting jump instructions at specific locations, the firmware program can jump to and execute the extension program inserted into the original unused space of the firmware. This can be done without affecting the normal use of the SSD, realizing the functional expansion of the firmware, which mainly includes executing remote code sent by the host, invoking timers, direct read and write flash memory, and self-destruction under specific circumstances. The availability of extended functions and the change in read and write performance after the expansion were experimentally tested.