The researchers found a serious vulnerability—CVE-2025-27840—in Espressif’s massively-deployed ESP32 chip, which is commonly used in various Internet-of-Things devices. This bug would make the security of Bitcoin wallets vulnerable. Malicious actors can use this vulnerability to circumvent safety measures. This allows them to steal private keys, which are essential for accessing and using cryptocurrency. That’s the case with these Bitcoin wallets that use the China-manufactured ESP32 chip.
Espressif Systems, one of China’s top tech companies, produces the popular ESP32 chip. The vulnerability allows remote unauthenticated attackers to produce false ECDSA signatures. These signatures are used to sign Bitcoin transactions, de facto giving full control of those digital assets without permission.
The chip’s Bluetooth and Wi-Fi capabilities significantly raise the threat of exploitation. Since hackers can deploy malicious updates from afar, they’re able to more easily target wallets that are still vulnerable.
In one of those tests, researchers were successfully able to exploit CVE-2025-27840 in a controlled, real-world scenario. The demonstration managed to open a user’s Bitcoin wallet with 10 BTC worth about USD 2000. Even more alarming, it points to the growing real risk of severe financial harm.
Attackers can use various methods to gain access to the private key data of Bitcoin wallets through ESP32. - Crypto Deep Tech
An estimated tens of millions of dollars in digital assets around the world are now at risk of theft due to this vulnerability. The recent discovery of CVE-2025-27840 has sparked conversations regarding the trustworthiness of Chinese built parts in key financial infrastructure.
