CVE-2021-28135 : What You Need to Know
Learn about CVE-2021-28135, a vulnerability in Espressif ESP-IDF allowing denial of service attacks on ESP32 devices. Find out about impacts, affected systems, and mitigation steps.
Espressif ESP-IDF 4.4 and earlier versions are vulnerable to a denial of service (DoS) attack due to improper handling of continuous unsolicited LMP responses in the Bluetooth Classic implementation. Attackers within radio range can exploit this issue to crash ESP32 by flooding it with LMP Feature Response data.
Understanding CVE-2021-28135
This section provides insights into the impact and technical details of CVE-2021-28135.
What is CVE-2021-28135?
The vulnerability in Espressif ESP-IDF allows attackers in radio range to trigger a denial of service (crash) in ESP32 by exploiting the Bluetooth Classic implementation.
The Impact of CVE-2021-28135
The vulnerability can lead to a DoS condition in ESP32 devices, causing them to crash when flooded with LMP Feature Response data.
Technical Details of CVE-2021-28135
Let's delve into the specifics of the vulnerability in terms of its description, affected systems, and exploitation mechanism.
Vulnerability Description
Espressif ESP-IDF 4.4 and earlier versions are susceptible to a DoS attack as attackers can exploit the Bluetooth Classic implementation to crash ESP32 devices.
Affected Systems and Versions
The vulnerability impacts ESP-IDF 4.4 and earlier versions, specifically in the Bluetooth Classic implementation of ESP32 devices.
Exploitation Mechanism
By flooding the target ESP32 with continuous unsolicited LMP responses, attackers within radio range can trigger a crash by exploiting the improper handling of LMP Feature Response data.
Mitigation and Prevention
In this section, we discuss the immediate steps to take and best practices for long-term security.
Immediate Steps to Take
It is recommended to apply security patches and updates provided by Espressif to mitigate the vulnerability in ESP-IDF 4.4 and earlier versions.
Long-Term Security Practices
Ensure regular monitoring of security advisories and updates from Espressif to protect against potential exploits.
Patching and Updates
Stay informed about security patches released by Espressif for ESP-IDF to address vulnerabilities and enhance the security of ESP32 devices.