CVE-2025-54484: Stack-Based Buffer Overflow Vulnerability in Biosig Project’s libbiosig 3.9.0

Overview

The Biosig Project’s libbiosig 3.9.0 and Master Branch (35a819fa) are plagued by a critical vulnerability, specifically a stack-based buffer overflow that can be exploited via a specially crafted MFER file. This vulnerability has far-reaching implications, affecting any system utilizing this widely-used library for biosignal processing. It’s crucial for system administrators and developers to understand the gravity of this vulnerability, as successful exploitation could lead to arbitrary code execution, potential system compromise or data leakage.

Vulnerability Summary

CVE ID: CVE-2025-54484
Severity: Critical (CVSS: 9.8)
Attack Vector: Network
Privileges Required: None
User Interaction: Required
Impact: Arbitrary code execution, potential system compromise, and data leakage.

Affected Products

Product | Affected Versions

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

How the Exploit Works

The stack-based buffer overflow vulnerability exists in the MFER parsing functionality of the Biosig Project’s libbiosig library. The vulnerability manifests when the Tag is 6, as described in line 8779 of biosig.c on the current master branch (35a819fa). An attacker can exploit this vulnerability by providing a specially crafted MFER file that triggers this overflow, leading to arbitrary code execution.

Conceptual Example Code

This is a conceptual representation of how the vulnerability might be exploited.

#include <stdio.h>
#include <stdlib.h>
int main() {
FILE *file;
char buf[4];
int len = 5;
// Open file in write mode.
file = fopen("malicious.MFER", "w");
// Write to file.
fwrite(buf, 1, len, file);
// Close file.
fclose(file);
return 0;
}

In this example, a file named “malicious.MFER” is created with a buffer size of 4 but a length of 5. When this file is processed by the vulnerable function, it will trigger a buffer overflow due to the mismatch between buffer size and length.

Recommendation

It is highly recommended to apply the vendor patch as soon as it becomes available. Until then, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary measure to mitigate the risk of exploitation. It is also crucial to monitor system logs for any suspicious activities that may indicate an attempt to exploit this vulnerability.