SB2019051304 - Privilege escalation in Espressif ESP-IDF

Description

This security bulletin contains information about 1 security vulnerability.

1) Input validation error (CVE-ID: CVE-2018-18558)

The vulnerability allows a local attacker to execute arbitrary code on the target system.

The vulnerability exists due to insufficient validation of user-supplied input in the 2nd stage bootloader. A local attacker with physical access can craft an application binary that overwrites a bootloader code segment in "process_segment" in "components/bootloader_support/src/esp_image_format.c.", bypass secure boot checks and execute arbitrary code on the target system.

Note: The attack is effective when the flash encryption feature is not enabled, or if the attacker finds a different vulnerability that allows them to write this binary to flash memory.

Remediation

Install update from vendor's website.

References

• https://github.com/espressif/esp-idf/releases
• https://www.espressif.com/en/news/Espressif_Product_Security_Advisory_Concerning_Secure_Boot_(CVE-2018-18558)