CVE-2025-53022 is a stack-based buffer overflow vulnerability found in TrustedFirmware-M, which is the Trusted Firmware implementation for Arm Cortex-M profile CPUs. Specifically, versions prior to 2.1.3 and 2.2.x before 2.2.1 are affected. The vulnerability arises in the Firmware Upgrade (FWU) module during the processing of a new firmware image. The FWU module uses a Type-Length-Value (TLV) structure to parse dependent components within the firmware upgrade image. However, it fails to properly validate the length field of the TLV against the maximum allowed buffer size allocated on the stack. If an attacker crafts a malicious TLV entry with a length field exceeding the buffer size, this causes a stack buffer overflow, overwriting adjacent stack memory with attacker-controlled data. This can lead to arbitrary code execution or system instability during the firmware upgrade process. The attack vector requires the attacker to supply a malicious MCUBoot upgrade image containing the malformed TLV entry in the unprotected section, which is processed without sufficient validation. Although no known exploits are currently reported in the wild, the vulnerability presents a significant risk due to the critical role of firmware in device security and operation. The lack of length validation is a classic programming error that can be exploited to compromise the integrity and availability of embedded systems running TrustedFirmware-M on Arm Cortex-M CPUs.

For European organizations, this vulnerability poses a serious threat to embedded systems and IoT devices that rely on TrustedFirmware-M for secure boot and firmware upgrades. Many industrial control systems, automotive ECUs, medical devices, and critical infrastructure components in Europe use Arm Cortex-M based microcontrollers with TrustedFirmware-M. Exploitation could allow attackers to execute arbitrary code during firmware updates, potentially leading to device bricking, persistent malware implantation, or disruption of critical services. This could impact sectors such as manufacturing, healthcare, automotive, and energy, where embedded devices are integral. The compromise of firmware integrity undermines the trustworthiness of device operation and can facilitate further lateral movement or sabotage. Given the increasing reliance on connected embedded devices in European critical infrastructure and industry, the vulnerability could have cascading effects on operational continuity and safety.

Organizations should immediately verify the versions of TrustedFirmware-M deployed in their embedded devices and ensure they are updated to at least version 2.1.3 or 2.2.1, where this vulnerability is fixed. Firmware upgrade processes should be hardened by implementing strict validation of TLV length fields before processing. Additionally, employing secure boot mechanisms that verify firmware signatures and integrity prior to upgrade can prevent unauthorized or malformed images from being accepted. Device manufacturers should provide updated firmware images and patches, and organizations must establish secure firmware update channels with cryptographic protections. For devices already deployed, network segmentation and monitoring of firmware upgrade traffic can help detect and block malicious upgrade attempts. Where possible, runtime protections such as stack canaries and control flow integrity should be enabled to mitigate exploitation impact. Finally, organizations should conduct thorough security testing of firmware upgrade components to identify and remediate similar vulnerabilities proactively.