The popular microcontroller used in billions of IoT devices and crypto wallets contains serious vulnerabilities that threaten bitcoin theft.
The vulnerability, which received the identifier CVE-2025-27840 in the NIST database, affects the ESP32 chip used for Wi-Fi and Bluetooth connectivity. The bug allows attackers to permanently infect microcontrollers via updates, providing opportunities for future attacks.
After a breach, attackers can unauthorizedly sign crypto transactions and remotely steal private keys.
The microcontroller installed in hardware wallets like Blockstream Jade also has insufficient entropy in the pseudo-random number generator (PRNG) used for creating transaction signatures. This allows attackers to guess key pairs through brute force.
During the experiments, specialists checked the vectors of possible attacks through identified vulnerabilities. The implementation of scripts allowed:
- generate invalid private keys by exploiting PRNG flaws;
- forge bitcoin signatures due to incorrect hashing;
- extract private keys using small group attacks and manipulation of ECC cryptographic operations;
- generate fake public keys by exploiting the ambiguity of the Y coordinate on the ECC curve.
In their research, Crypto Deep Tech experts used a real wallet with 10 BTC.
“Implementing robust protection mechanisms and regular security updates are key elements to ensuring the secure and reliable operation of digital systems. The need to enhance security in devices and networks, such as ESP32, is becoming increasingly relevant,” concluded the specialists.
Recall that in March, the hardware wallet manufacturer Trezor fixed a vulnerability in the Safe 3 and Safe 5 models. The issue was related to the microcontroller used for cryptographic operations.#VoteToDelistOnBinance
