When analyzing the external SSD Verbatim Store n Go Secure Portable HDD, Matthias Deeg found out that the validation of the firmware for the USB-to-SATA bridge controller INIC-3637EN only consists of a simple CRC-16 check (XMODEM CRC-16). Thus, an attacker is able to store malicious firmware code for the INIC-3637EN with a correct checksum on the used SPI flash memory chip (XT25F01D), which then gets successfully executed by the USB-to-SATA bridge controller. For instance, this security vulnerability could be exploited in a so-called "supply chain attack" when the device is still on its way to its legitimate user. An attacker with temporary physical access during the supply could program a modified firmware on the Verbatim Keypad Secure, which always uses an attacker-controlled AES key for the data encryption, for example. If, later on, the attacker gains access to the used USB drive, he can simply decrypt all contained user data. Continue reading...
