The hidden risk of updatable firmware

Igor Zemtsov, chief technology officer at TBCC, argues that updatable hardware wallet firmware is a security risk, since each update can introduce flaws or deliberate backdoors that users cannot verify. He cites Ledger's 2018 vulnerability, disclosed by security researcher Saleem Rashid, which could let attackers replace Ledger Nano S firmware and hijack private keys on nearly 1 million devices. He also points to the 2023 OneKey firmware cracking demonstration and the "Dark Skippy" exploit. He presents Tangem's fixed, non-updatable firmware as an alternative, acknowledging that vulnerabilities then cannot be patched.