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CVE-2025-27840 is a vulnerability affecting Espressif ESP32 chips in which 29 undocumented Bluetooth Host Controller Interface commands are exposed in production devices. Reported functionality includes commands capable of reading and writing memory, including RAM and flash, as well as lower-level Bluetooth controller operations such as packet injection and MAC address manipulation. The commands were described as internal debugging and test functionality within the Bluetooth HCI implementation, but their presence in deployed ESP32-based products creates an attack surface that can be abused to alter device state and behavior. Because ESP32 components are embedded across a wide range of smart and IoT products, the affected population is broad and not exhaustively enumerated.
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2 valid exploits after Mallory filtered fakes, detection scripts, and README-only repos (2 hidden).
This repository is a small, focused reproduction and side-channel experimentation project for CVE-2025-27840 affecting undocumented Bluetooth HCI vendor commands on ESP32 devices. It is not a remote over-the-air exploit; the included documentation explicitly states the issue requires a secondary/local attack path, and the code operates through the ESP32 controller HCI UART interface. Repository structure: (1) README.md gives the high-level purpose: capture power traces while sending undocumented HCI commands; (2) docs/ESP32_Undocumented_Bluetooth_Commands_CVE-2025-27840.md is a detailed lab guide covering board setup, flashing vulnerable/fixed ESP-IDF versions, UART wiring, and trace-hook modifications; (3) scripts/esp32_undocumented_commands.py is the main host-side exploit/interaction script; (4) trigger-mechanisms/trace_hook.c is modified ESP-IDF example firmware that initializes Bluetooth HCI UART and toggles a GPIO trigger when the btController task is scheduled; (5) trigger-mechanisms/FreeRTOSConfig.h is a patched FreeRTOS configuration file used to enable trace hooks in ESP-IDF v5.0.x. Main exploit capabilities are in the Python script. It constructs raw HCI command packets with packet type 0x01 and vendor-specific opcodes in the 0xFCxx range. The opcode table includes hidden commands such as READ_MEM (0xFC01), WRITE_MEM (0xFC02), flash read/write/erase, register read/write, MAC setting, reset, and packet manipulation commands. The implemented helpers specifically support arbitrary memory write and read by supplying a 32-bit target address, access size, and length. The example code writes attacker-controlled bytes to address 0x3fff0000 and then reads them back, demonstrating practical memory access against the controller. Response parsing expects HCI event packets (0x04) with Command Complete (0x0E). The firmware component is not itself an exploit payload but an instrumentation aid. It adapts Espressif's controller_hci_uart_esp32 example to disable hardware flow control if desired, initialize the Bluetooth controller, locate the btController task, and pulse GPIO 27 inside a trace hook whenever that task is switched in. This is intended to synchronize external power-trace capture equipment with Bluetooth controller activity while testing undocumented commands on vulnerable versus fixed firmware. Overall, this is an operational local PoC/reproduction toolkit for exercising undocumented ESP32 Bluetooth controller commands and observing side-channel behavior before and after the vendor fix. It combines a host-side UART command sender with target-side firmware modifications for measurement and experimentation.
This repository is a proof-of-concept (POC) exploit toolkit targeting cryptographic vulnerabilities in ESP32 microcontrollers (CVE-2025-27840), with a focus on attacks against Bitcoin wallets and related cryptographic operations. The codebase consists of Python scripts that demonstrate various cryptographic attacks, including: - Invalid private key acceptance due to missing lower bound checks (secp256k1_privkey_validator.py) - Signature forgery and message hash manipulation (bitcoin_sign_hash.py, calculate.py) - Invalid curve attacks and demonstration of ECC multiplication vulnerabilities (ecdsa_curve_attack.py) - Weak or predictable key generation (privkey_generate.py) - Exploitation of weak or custom RIPEMD160 hash implementations (ripemd160_vulnerability.py) - Recovery of private keys or public keys from weak ECDSA signatures (weak_key_recovery.py) - Conversion and manipulation of Bitcoin addresses and keys (priv_addr.py, wif_to_hash160.py) The repository includes sample data files (KEYFOUND.privkey, RawTX.txt) with example private keys and transactions. The main attack vectors are network-based (exploiting devices via Wi-Fi/Bluetooth) and local (attacking cryptographic operations on the device). The code is intended for research and demonstration purposes, highlighting the risks of insecure cryptographic implementations in IoT devices, especially those handling cryptocurrency wallets. No weaponized or automated exploitation is present, but the scripts provide a foundation for further development.
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31 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An ESP32 hardware vulnerability referenced as causing weak nonce generation, which in turn enabled recovery of cryptocurrency wallet private keys from ECDSA signatures.
An ESP32 hardware vulnerability cited as causing weak ECDSA nonce generation, enabling private key recovery from Bitcoin wallet signatures.
An ESP32 hardware vulnerability referenced as causing weak nonce generation, enabling private key recovery from affected Bitcoin wallet signatures.
A purported hardcoded private key vulnerability described as enabling private key recovery in Bitcoin-related software.
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Cross-references every affected SKU, including bundled OEM variants.
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