CVE-2025-54482: Critical Stack-Based Buffer Overflow Vulnerability in The Biosig Project libbiosig

Overview

A critical vulnerability has been discovered in the Biosig Project libbiosig software, specific to its MFER parsing functionality. This vulnerability, tagged as CVE-2025-54482, exposes systems to potential compromise and data leakage. By exploiting this flaw, an attacker can execute arbitrary code, thereby gaining unauthorized access to sensitive data or control over the system. This vulnerability is particularly noteworthy due to its high severity score, and the widespread use of the Biosig Project libbiosig in various sectors.

Vulnerability Summary

CVE ID: CVE-2025-54482
Severity: Critical (CVSS: 9.8)
Attack Vector: Specially crafted MFER file
Privileges Required: None
User Interaction: Required (An attacker needs to provide a malicious file to trigger this vulnerability)
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 manifests due to a stack-based buffer overflow in the MFER parsing functionality of the Biosig Project libbiosig. If an attacker crafts a specific MFER file that exploits this flaw, they can execute arbitrary code. This happens on line 8751 of biosig.c on the current master branch (35a819fa), when the Tag is 4.

Conceptual Example Code

Here’s a simplified conceptual example of how the exploit might work:

// Attacker creates a malicious MFER file
void maliciousMFERfile() {
char buf[4];
FILE *hdr;
// Set the Tag to 4
int tag = 4;
// Set the length greater than 4 to trigger the buffer overflow
int len = 5;
if (tag == 4) {
if (len > 4) {
fprintf(stderr, "Warning MFER tag4 incorrect length %i>4\n", len);
curPos += ifread(buf, 1, len, hdr);
}
}
}

This piece of code could generate a malicious MFER file that, when parsed by the vulnerable Biosig Project libbiosig functionality, would trigger the buffer overflow and lead to arbitrary code execution.

Mitigation Guidance

To mitigate this vulnerability, users are strongly advised to apply the vendor patch as soon as it is available. As a temporary measure, users can employ a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to detect and block attempts to exploit this vulnerability. Regular monitoring of system logs, and isolation of affected systems can also help in limiting the potential damage.