CVE-2025-53853: Buffer Overflow Vulnerability in Biosig Project libbiosig

Overview

The Biosig Project libbiosig, a popular biosignal processing library, has been discovered to contain a severe heap-based buffer overflow vulnerability. This vulnerability, allocated the identifier CVE-2025-53853, affects version 3.9.0 and the Master Branch (35a819fa) of libbiosig. The exploitation of this vulnerability could lead to arbitrary code execution, potentially compromising the entire system or leading to data leakage. This vulnerability is of significant importance due to its high severity and the widespread use of the Biosig Project’s libbiosig in the healthcare industry.

Vulnerability Summary

CVE ID: CVE-2025-53853
Severity: Critical (CVSS 9.8)
Attack Vector: File
Privileges Required: None
User Interaction: Required
Impact: System compromise and potential data leakage

Affected Products

Product | Affected Versions

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

How the Exploit Works

The vulnerability resides in the ISHNE parsing functionality of libbiosig. An attacker can exploit this vulnerability by crafting a malicious ISHNE ECG annotations file. When this file is processed by the vulnerable software, it triggers a buffer overflow. This overflow occurs because the software fails to properly validate the size of the input data before copying it to a fixed-size buffer. This can lead to overwriting of adjacent memory spaces, allowing the attacker to execute arbitrary code.

Conceptual Example Code

Given that the vulnerability occurs during the parsing of an ISHNE ECG annotations file, the exploit would likely involve the creation of such a file with specially designed data to trigger the overflow. A conceptual example might look like this:

#include <stdio.h>
#include <string.h>
int main(void) {
char buffer[512];
FILE *fp;
memset(buffer, 'A', sizeof(buffer)-1); // Fill the buffer with 'A's
buffer[sizeof(buffer)-1] = '\0'; // Null terminate the string
fp = fopen("malicious.ishne", "w");
fwrite(buffer, sizeof(char), sizeof(buffer), fp); // Write the buffer to the file
fclose(fp);
return 0;
}

This conceptual example creates a malicious ISHNE ECG annotations file that contains a string of ‘A’s longer than the buffer size. When the file is processed by the vulnerable software, it would trigger the buffer overflow.

Recommended Mitigation

Users are advised to apply the vendor patch immediately if available. If the patch is not available or if immediate patching is not feasible, users should consider using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as a temporary mitigation measure to detect and block attempts to exploit this vulnerability.