CVE-2025-54482 is a critical stack-based buffer overflow vulnerability identified in The Biosig Project's libbiosig library, specifically affecting versions 3.9.0 and the current master branch (commit 35a819fa). The vulnerability resides in the MFER (Multi-File EEG Record) parsing functionality, where improper handling of the 'Tag 4' data leads to a buffer overflow on the stack. The problematic code segment, located around line 8751 in biosig.c, fails to properly validate the length of the input data before reading it into a fixed-size buffer. When a specially crafted MFER file with a malicious payload is processed, this unchecked input can overwrite the stack memory, enabling an attacker to execute arbitrary code remotely without any authentication or user interaction. The vulnerability has a CVSS v3.1 base score of 9.8, reflecting its critical nature with network attack vector, low attack complexity, no privileges required, and no user interaction needed. The impact includes full compromise of confidentiality, integrity, and availability of affected systems. Although no known exploits are currently reported in the wild, the severity and ease of exploitation make it a significant threat to any environment utilizing libbiosig for EEG data processing or related biomedical signal analysis.

European organizations that rely on The Biosig Project's libbiosig library, particularly in medical, research, or healthcare sectors handling EEG and biosignal data, face substantial risk from this vulnerability. Exploitation could lead to remote code execution, allowing attackers to gain unauthorized access to sensitive patient data, disrupt medical device functionality, or compromise research integrity. Given the criticality of healthcare infrastructure in Europe and stringent data protection regulations such as GDPR, a breach could result in severe operational disruptions, legal penalties, and reputational damage. Additionally, research institutions using libbiosig for neurological or biomedical studies may suffer data corruption or loss, impacting scientific outcomes. The vulnerability's network accessibility and lack of required privileges increase the likelihood of widespread exploitation if unpatched, potentially affecting hospitals, clinics, and academic centers across Europe.

To mitigate this vulnerability, European organizations should immediately audit their use of libbiosig versions 3.9.0 and the master branch (35a819fa) in their software stacks. Since no official patch links are currently available, organizations should consider the following specific actions: 1) Temporarily disable or restrict processing of MFER files from untrusted sources to prevent malicious input. 2) Implement network-level controls such as firewalls and intrusion prevention systems to monitor and block suspicious MFER file transfers. 3) Conduct code reviews and apply manual patches by adding strict input validation on the length of Tag 4 data before buffer reads, ensuring it does not exceed buffer capacity. 4) Engage with The Biosig Project community or maintainers for timely updates or patches. 5) Employ runtime protections like stack canaries, address space layout randomization (ASLR), and control flow integrity (CFI) in applications using libbiosig to reduce exploitation risk. 6) Monitor security advisories for exploit developments and apply patches promptly once available. 7) Educate staff on the risks of processing untrusted biosignal files and enforce strict file handling policies.