CVE-2025-54488: 
Linux Debian vulnerability analysis and mitigation

A stack-based buffer overflow vulnerability (CVE-2025-54488) exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa). The vulnerability was discovered and reported by Cisco Talos on August 25, 2025. This vulnerability affects the MFER file parsing component when processing medical signal data (Talos, NVD).

The vulnerability manifests on line 8850 of biosig.c on the current master branch (35a819fa), when the Tag is 13. The issue occurs in the sopenextended function, which is the common entry point for file parsing. When processing MFER files with Tag 13, the code attempts to read an unvalidated length into a statically-sized 128-byte stack-allocated buffer, potentially leading to a buffer overflow. The vulnerability has been assigned a CVSS v3.1 base score of 9.8 (CRITICAL) with vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H and is classified as CWE-121 (Stack-based Buffer Overflow) ([Talos](https://talosintelligence.com/vulnerabilityreports/TALOS-2025-2234)).

The vulnerability can lead to arbitrary code execution when a specially crafted MFER file is processed. An attacker can provide a malicious file to trigger this vulnerability, potentially gaining control over the affected system. Given the CVSS score of 9.8, this represents a critical security risk with potential for complete system compromise (Talos).

The vulnerability affects The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa). Users should update to a patched version when available. No specific workarounds have been published at the time of this report (Talos).