CVE-2025-54494: Buffer Overflow Vulnerability in The Biosig Project libbiosig

Overview

A critical vulnerability has been identified in The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa), an open-source library providing free access to biomedical signal data. The vulnerability, officially indexed as CVE-2025-54494, is a stack-based buffer overflow that potentially allows an attacker to execute arbitrary code. The severity of this vulnerability is high, as it can potentially lead to a full system compromise or data leakage if successfully exploited. It’s critical for all users and administrators of the affected software to understand this vulnerability, apply necessary patches, or implement recommended mitigations.

Vulnerability Summary

CVE ID: CVE-2025-54494
Severity: Critical – CVSS Score of 9.8
Attack Vector: Remote
Privileges Required: None
User Interaction: Required
Impact: Unauthorized execution of arbitrary code leading to potential system compromise or data leakage

Affected Products

Product | Affected Versions

The Biosig Project libbiosig | 3.9.0 and Master Branch (35a819fa)

How the Exploit Works

The vulnerability resides in the MFER parsing functionality of the affected software. An attacker can exploit this vulnerability by crafting a malicious MFER file and convincing the victim to open it using the vulnerable software. This triggers a buffer overflow condition, ultimately leading to the execution of arbitrary and potentially malicious code.

Conceptual Example Code

While the exact exploit code has not been disclosed to prevent misuse, a conceptual example of the exploit could look like this:

# Define malicious payload
buffer = "A" * 5000 # Buffer overflow trigger
# Create malicious MFER file
with open('malicious.mfer', 'w') as file:
file.write(buffer)
# The malicious.mfer file is then provided to the victim
# who opens it with the vulnerable libbiosig software

This is a simplified representation and actual exploitation scenarios may vary and require more complex code. Nonetheless, it demonstrates the fundamental principle of the exploit – overflowing the buffer to execute arbitrary code.

Mitigation

The recommended mitigation for this vulnerability is to apply the patch provided by the vendor. In cases where immediate patching is not possible, temporary mitigation can be achieved by deploying a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to monitor and block malicious activities. All users are advised to stay vigilant when receiving files from unknown sources, and to only open files that are from trusted and verified sources.