The Bluetooth Classic implementation in Espressif ESP-IDF 4.4 and earlier does not properly handle the reception of continuous unsolicited LMP responses, allowing attackers in radio range to trigger a denial of service (crash) in ESP32 by flooding the target device with LMP Feature Response data.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-28135
• https://dl.packetstormsecurity.net/papers/general/braktooth.pdf
• https://github.com/espressif/esp-idf
• https://github.com/espressif/esp32-bt-lib
• https://www.espressif.com/en/products/socs/esp32