CVE-2025-54483 is a stack-based buffer overflow vulnerability identified in The Biosig Project's libbiosig library, specifically in the MFER file parsing code. The flaw occurs in versions 3.9.0 and the master branch (commit 35a819fa) within biosig.c at line 8759, where the code improperly handles the length of data associated with tag 5, which represents the number of channels. The vulnerable code fails to adequately validate the length parameter before reading data into a fixed-size buffer on the stack, allowing a specially crafted MFER file to overflow the buffer. This overflow can overwrite the stack, leading to arbitrary code execution under the privileges of the process using libbiosig. The vulnerability is exploitable remotely without authentication or user interaction, as an attacker only needs to supply a malicious MFER file to a vulnerable application. The CVSS v3.1 score of 9.8 reflects the critical nature of this vulnerability, with high impact on confidentiality, integrity, and availability. No public exploits are currently known, but the vulnerability's characteristics suggest it could be weaponized quickly once details become widespread. Libbiosig is used primarily in biomedical signal processing, including EEG and other biosignal data analysis, making the vulnerability particularly relevant to healthcare and research environments. The lack of an available patch at the time of disclosure increases the urgency for mitigations and monitoring.

The impact of CVE-2025-54483 on European organizations is significant, especially those in healthcare, biomedical research, and related industries that utilize libbiosig for biosignal processing. Successful exploitation can lead to arbitrary code execution, allowing attackers to compromise system confidentiality by accessing sensitive patient or research data, integrity by altering biosignal data or analysis results, and availability by causing system crashes or denial of service. Given the critical nature of healthcare data and the reliance on accurate biosignal processing, this vulnerability could disrupt medical diagnostics, research outcomes, and patient care. Additionally, compromised systems could be leveraged as entry points for broader network intrusions or ransomware attacks. The vulnerability's remote exploitability without authentication increases the risk of widespread attacks, particularly in environments where untrusted MFER files might be processed automatically or without sufficient validation. European healthcare providers, research institutions, and medical device manufacturers are therefore at heightened risk, potentially impacting patient safety and regulatory compliance under GDPR and medical device regulations.

To mitigate CVE-2025-54483, European organizations should immediately audit their use of libbiosig and identify any systems processing MFER files. Although no official patch is currently available, organizations should implement strict input validation to reject malformed or suspicious MFER files, particularly those with unexpected tag lengths. Employ sandboxing or containerization of applications handling biosignal data to limit the impact of potential exploitation. Network-level protections such as file integrity monitoring, intrusion detection systems tuned for anomalous MFER file activity, and restricting file sources to trusted origins can reduce exposure. Organizations should also monitor security advisories from The Biosig Project for patches or updates and plan rapid deployment once available. Additionally, applying compiler-level protections like stack canaries, ASLR, and DEP on affected systems can help mitigate exploitation risks. Training staff to recognize suspicious files and enforcing strict access controls on biosignal processing systems further reduce attack surfaces.