An issue was discovered on Espressif ESP32 3.0 (ESP32_rev300 ROM) devices. An EMFI attack on ECO3 provides the attacker with a capability to influence the PC value at the CPU context level, regardless of Secure Boot and Flash Encryption status. By using this capability, the attacker can exploit another behavior in the chip to gain unauthorized access to the ROM download mode. Access to ROM download mode may be further exploited to read the encrypted flash content in cleartext format or execute stub code.

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-35818
• https://espressif.com
• https://www.espressif.com/sites/default/files/advisory_downloads/AR2023-005%20Security%20Advisory%20Concerning%20Bypassing%20Secure%20Boot%20and%20Flash%20Encryption%20Using%20EMFI%20EN.pdf