The vulnerability CVE-2025-54482 is a stack-based buffer overflow in the MFER parsing functionality of The Biosig Project's libbiosig library, specifically in versions 3.9.0 and the master branch (commit 35a819fa). The issue arises in biosig.c at line 8751 when processing MFER files with tag 4, where the code does not properly enforce length constraints, allowing an attacker to supply a maliciously crafted MFER file that triggers a buffer overflow. This overflow can overwrite the stack, enabling arbitrary code execution without requiring any privileges or user interaction. The vulnerability is classified under CWE-121 (stack-based buffer overflow) and has a CVSS v3.1 score of 9.8, indicating critical severity with network attack vector, low attack complexity, no privileges required, and no user interaction needed. The flaw impacts confidentiality, integrity, and availability by allowing remote attackers to execute arbitrary code, potentially leading to full system compromise. The Biosig Project's libbiosig is used for biosignal processing, including biomedical signal analysis, making this vulnerability particularly relevant for healthcare and research applications. No patches are currently linked, and no known exploits have been reported in the wild, but the risk remains high due to the nature of the vulnerability and ease of exploitation.

The impact on European organizations is significant, especially those involved in healthcare, biomedical research, and any domain relying on biosignal data processing using libbiosig. Successful exploitation can lead to arbitrary code execution, allowing attackers to gain full control over affected systems, steal sensitive patient or research data, disrupt critical healthcare services, or use compromised systems as pivot points for further attacks. This can result in severe confidentiality breaches, data integrity loss, and service outages. Given the critical nature of healthcare infrastructure in Europe and strict data protection regulations such as GDPR, exploitation could also lead to substantial legal and financial consequences. Additionally, research institutions handling sensitive biomedical data could face intellectual property theft or sabotage. The lack of required authentication and user interaction increases the threat level, as attackers can remotely exploit vulnerable systems by simply providing a malicious MFER file.

Organizations should immediately audit their use of libbiosig, particularly versions 3.9.0 and the master branch, to identify vulnerable deployments. Although no official patches are currently linked, monitoring The Biosig Project repositories and security advisories for updates is critical. In the interim, implement strict input validation and sanitization on all MFER files before processing to detect and block malformed or suspicious files. Employ sandboxing or containerization to isolate the biosignal parsing processes, limiting the impact of potential exploitation. Network-level controls should restrict access to services that process MFER files to trusted sources only. Regularly update and patch all related software components once fixes become available. Conduct security awareness training for developers and administrators about secure handling of biosignal data and the risks of buffer overflows. Finally, implement runtime protections such as stack canaries, address space layout randomization (ASLR), and control flow integrity (CFI) where possible to mitigate exploitation.