CVE-2025-53853 is a heap-based buffer overflow vulnerability identified in The Biosig Project's libbiosig library, specifically within the ISHNE ECG annotations file parsing functionality. The affected versions are 3.9.0 and the master branch commit 35a819fa. The vulnerability arises when a specially crafted ISHNE ECG annotations file is processed, causing the parser to write beyond the allocated heap buffer boundaries. This memory corruption can be leveraged by an attacker to execute arbitrary code on the target system. The vulnerability requires no authentication or user interaction, and the attack vector is remote via supplying a malicious file to the system that uses libbiosig for ECG data processing. The CVSS v3.1 score of 9.8 reflects the critical nature of this flaw, with attack vector network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and impacts on confidentiality, integrity, and availability (C:H/I:H/A:H). Although no known exploits are currently reported in the wild, the severity and ease of exploitation make this a high-priority issue. The Biosig Project is widely used in medical and research environments for biosignal processing, making this vulnerability particularly concerning for healthcare data integrity and patient safety. The lack of available patches at the time of reporting necessitates immediate mitigation efforts.

The impact on European organizations is significant, especially those in healthcare, biomedical research, and medical device manufacturing that rely on libbiosig for ECG data processing. Exploitation could lead to arbitrary code execution, allowing attackers to compromise patient data confidentiality, alter medical records, or disrupt critical healthcare services. This could result in data breaches, regulatory non-compliance (e.g., GDPR violations), and potential harm to patients if medical devices or diagnostic systems are affected. The availability of healthcare systems could also be impaired, causing delays in diagnosis or treatment. Research institutions handling sensitive biosignal data may face intellectual property theft or sabotage. The critical severity and network-based attack vector mean that even perimeter defenses may be bypassed if malicious files are introduced via trusted channels or compromised endpoints. The reputational damage and financial costs associated with such breaches could be substantial for European healthcare providers and research entities.

1. Monitor The Biosig Project repositories and official channels for patches addressing CVE-2025-53853 and apply updates immediately upon release. 2. Until patches are available, implement strict input validation and sanitization on all ISHNE ECG annotation files before processing with libbiosig. 3. Employ sandboxing or containerization techniques to isolate the libbiosig parsing process, limiting the potential impact of exploitation. 4. Restrict file upload and processing privileges to minimal necessary accounts and environments to reduce attack surface. 5. Conduct thorough code audits and fuzz testing on the ISHNE parsing functionality to identify and remediate similar vulnerabilities proactively. 6. Deploy network and host-based intrusion detection systems configured to detect anomalous file inputs or suspicious process behaviors related to libbiosig. 7. Educate staff handling ECG data about the risks of processing files from untrusted sources. 8. Review and enhance logging and monitoring of systems processing biosignal data to enable rapid detection and response to exploitation attempts.