CVE-2025-54486: Critical Buffer Overflow Vulnerability in The Biosig Project libbiosig 3.9.0

Overview

In this blog post, we are going to discuss a critical vulnerability, CVE-2025-54486, that affects The Biosig Project libbiosig 3.9.0. This vulnerability is of particular concern due to its high severity rating, and the potential system compromise or data leakage it can result in if successfully exploited. Users and administrators of systems running The Biosig Project libbiosig 3.9.0 are advised to understand the implications of this vulnerability and take immediate steps to mitigate its risks.

Vulnerability Summary

CVE ID: CVE-2025-54486
Severity: Critical (CVSS: 9.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: 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 exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.0. A stack-based buffer overflow can be triggered by providing a specially crafted MFER file. If an attacker creates and sends a malicious MFER file to the system, they can trigger the overflow and execute arbitrary code on the targeted system. This vulnerability manifests on line 8824 of biosig.c on the current master branch (35a819fa), when the Tag is 11.

Conceptual Example Code

Here is a conceptual example of how the vulnerability might be exploited:

#include <stdio.h>
void exploit() {
// arbitrary code to be executed
}
void vulnerable_function(char *input) {
char buffer[6];
// overflow occurs here if input is larger than buffer
strcpy(buffer, input);
}
int main() {
char malicious_input[10] = "OVERFLOW";
// initiate overflow
vulnerable_function(malicious_input);
return 0;
}

In this example, a malicious input is used to overflow the buffer in the vulnerable_function, which could potentially allow for the execution of arbitrary code.

Mitigation

The recommended mitigation for this vulnerability is to apply the vendor-supplied patch as soon as it becomes available. If the patch is not immediately available, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation. These tools can help detect and prevent potential exploits of this vulnerability. However, they should not be considered a long-term solution, and the vendor-supplied patch should be applied as soon as possible.

Conclusion

The CVE-2025-54486 vulnerability in The Biosig Project libbiosig 3.9.0 is a serious threat that requires immediate attention. A successful exploit could result in system compromise and data leakage. Always ensure that your systems are running the latest available patches and are protected by robust security tools to mitigate the risk of such vulnerabilities.