CVE-2023-35818 : Security Advisory and Response

An issue was discovered on Espressif ESP32 3.0 (ESP32_rev300 ROM) devices that allows an attacker to gain unauthorized access to ROM download mode, potentially leading to the exposure of encrypted flash content or execution of unauthorized code.

Understanding CVE-2023-35818

This section will delve into the details of the CVE-2023-35818 vulnerability.

What is CVE-2023-35818?

CVE-2023-35818 refers to a security vulnerability present in Espressif ESP32 3.0 devices that enables an attacker to manipulate the CPU context level, bypass Secure Boot and Flash Encryption, and gain access to ROM download mode.

The Impact of CVE-2023-35818

The impact of this vulnerability includes the potential exposure of encrypted flash content in cleartext format and unauthorized execution of stub code due to unauthorized access to the ROM download mode.

Technical Details of CVE-2023-35818

This section will provide technical insights into the vulnerability.

Vulnerability Description

The vulnerability allows for an EMFI attack on ECO3 in ESP32 devices, providing the attacker with the ability to influence the PC value at the CPU context level and exploit another chip behavior for unauthorized access to ROM download mode.

Affected Systems and Versions

Espressif ESP32 3.0 (ESP32_rev300 ROM) devices are affected by this vulnerability.

Exploitation Mechanism

The attacker can exploit this vulnerability by leveraging the EMFI attack on ECO3 to manipulate the CPU context level and gain unauthorized access to the ROM download mode.

Mitigation and Prevention

This section will outline steps to mitigate and prevent exploitation of CVE-2023-35818.

Immediate Steps to Take

It is recommended to apply security patches provided by Espressif to address this vulnerability and prevent unauthorized access to sensitive information.

Long-Term Security Practices

Implementing secure boot mechanisms, flash encryption, and regular security audits can enhance the long-term security posture of ESP32 devices.

Patching and Updates

Regularly update firmware and security patches from Espressif to ensure the latest protections are in place to mitigate the CVE-2023-35818 vulnerability.