CVE-2024-57257 identifies a stack consumption vulnerability in the sqfs_size function of the denx U-Boot bootloader prior to version 2025.01-rc1. The issue stems from uncontrolled recursion caused by processing a crafted squashfs filesystem image that contains deeply nested symbolic links. When U-Boot attempts to parse such a filesystem, the recursive calls to resolve symlinks can consume excessive stack space, potentially leading to a stack overflow or exhaustion. This condition may cause the bootloader to crash or behave unpredictably, resulting in a denial of service during the boot process. The vulnerability is classified under CWE-674 (Uncontrolled Recursion), which highlights the risk of recursive function calls without proper termination conditions or depth limits. Exploitation requires an attacker to supply a malicious squashfs image to the device, which typically implies local or physical access or control over the firmware update process. The CVSS v3.1 base score is 2.0, reflecting low severity due to the high attack complexity, lack of privileges required, no user interaction, and limited impact confined to availability. No known public exploits or active exploitation have been reported. The vulnerability affects all versions of U-Boot before 2025.01-rc1, a widely used open-source bootloader in embedded systems, IoT devices, and industrial equipment. Since U-Boot is often used in critical infrastructure and embedded environments, this vulnerability could disrupt device availability if exploited, but it does not compromise confidentiality or integrity of the system. No patches were linked at the time of reporting, but upgrading to the fixed version is the recommended remediation.

For European organizations, the primary impact of CVE-2024-57257 is a potential denial of service during device boot due to stack exhaustion caused by maliciously crafted squashfs images. This could disrupt operations in environments relying on embedded devices or industrial control systems that use U-Boot as their bootloader. While the vulnerability does not allow data theft or unauthorized code execution, availability interruptions could affect critical infrastructure, manufacturing lines, or IoT deployments. The requirement for local or physical access to supply the malicious filesystem limits remote exploitation risks, but insider threats or supply chain attacks could leverage this vulnerability. Organizations with extensive embedded device fleets, such as automotive manufacturers, telecommunications providers, and industrial automation companies, may face operational disruptions if devices are not updated. However, the low CVSS score and absence of known exploits reduce the immediate threat level. Still, failure to address this vulnerability could increase risk exposure in environments where device uptime is critical.

To mitigate CVE-2024-57257, European organizations should: 1) Monitor for and apply updates to U-Boot, specifically upgrading to version 2025.01-rc1 or later once officially released, as this version contains the fix for the uncontrolled recursion issue. 2) Implement strict validation and integrity checks on squashfs filesystem images before deployment to embedded devices, ensuring they do not contain maliciously crafted deep symlink nesting. 3) Restrict physical and local access to devices running U-Boot to prevent unauthorized firmware or filesystem modifications. 4) Incorporate secure boot mechanisms and firmware signing to prevent loading of unauthorized or tampered boot images. 5) Conduct regular security audits of embedded device firmware and bootloader configurations to detect anomalies. 6) Collaborate with device vendors and supply chain partners to ensure patched bootloader versions are integrated into device firmware. 7) Develop incident response plans that include recovery procedures for embedded device failures caused by bootloader issues. These steps go beyond generic advice by focusing on supply chain security, firmware validation, and physical access controls tailored to embedded environments common in Europe.