DARKNAVY shows tampered Cypherock X1 firmware passing the authenticity check at GEEKCON

At GEEKCON 2025 in Shanghai, a security contest and conference founded by the research firm DARKNAVY, DARKNAVY demonstrated attacks on two hardware wallets, one of them the Cypherock X1. On 21 November 2025 it published a technical write-up. According to DARKNAVY, it simulated a supply-chain attack: it tampered with the X1’s firmware, bypassed secure boot and the device authenticity check, and gained control over newly generated recovery phrases. On stage, a judge connected the modified wallet to Cypherock’s cySync software, and the authenticity check reported the device as verified on both the computer and the wallet screen.

DARKNAVY describes a chain of weaknesses on the X1 Vault’s microcontroller. An out-of-bounds access when the wallet selects an applet by the ID in a USB packet lets an attacker take over code execution. A flaw in the STM32L4 firewall interface lets the protected firewall code be copied out and read. The firmware upgrade steps can be run out of order, and on boot the firmware is checked only for integrity, not for a valid signature. Finally, the authenticity check signs a firmware hash supplied by the firmware itself and is one-way: the cloud verifies the device, but the device does not verify the cloud. DARKNAVY says the chain runs entirely on the Vault’s microcontroller and does not involve the secure element or the X1 Cards. It notes that the bootloader and firewall code are not open source and are designed not to be upgradeable.

GEEKCON’s published slides for the session add a second scenario: with code running on the microcontroller, an attacker who already controls the victim’s computer can steal private keys once the owner connects and unlocks the wallet. The slides say the X1’s recovery phrase is generated directly by the microcontroller, and that the private key sits in its memory while the device is unlocked.

DARKNAVY states that it reported two vulnerabilities to Cypherock by email in March 2025, and that Cypherock pushed patches to GitHub without acknowledging the reports. Neither DARKNAVY’s write-up nor GEEKCON’s slides mention a fix for the bootloader and firewall flaws used in the demonstration, and no Cypherock statement on the demonstration was found.