CVE-2023-51712

Vulnerability

An issue was discovered in Trusted Firmware-M through v2.0.0 where the logging subsystem, when enabled via TFM_SP_LOG_RAW_ENABLED=1 in IPC mode, lacks argument verification. This allows for sensitive data to be read via the login function, which is accessible through a crafted SVC call [1].

Exploitation

An attacker, specifically a malicious Application Root of Trust (ARoT) partition, can exploit this vulnerability by creating an alternative SVC call to the logging subsystem. This bypasses MPU protections and allows the attacker to send arbitrary memory data to the stdout device, typically UART, by leveraging the SVC handler's high privilege level and memory access [1].

Impact

Successful exploitation allows a malicious ARoT partition to expose any part of memory to the stdout device. This occurs when the logging subsystem is enabled and PSA isolation level 2 or higher is configured, potentially leading to the disclosure of sensitive data [1].

Mitigation

A fix has been implemented by adding tfm_hal_memory_check to the logging function's SVC handler to ensure data belongs to the current partition. If the check fails, the system halts via tfm_core_panic(). The fixed version is not yet disclosed in the available references [1].