CVE-2025-54481

Comprehensive Technical Analysis of CVE-2025-54481

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2025-54481

Description: A stack-based buffer overflow vulnerability exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa). This vulnerability can be exploited by providing a specially crafted MFER file, leading to arbitrary code execution.

Severity: The CVSS score of 9.8 indicates a critical vulnerability. This high score is due to the potential for remote code execution, which can have severe consequences including system compromise, data breaches, and unauthorized access.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Malicious File Upload: An attacker can craft an MFER file with a malicious payload designed to exploit the buffer overflow. This file can be uploaded to a system that processes MFER files using the vulnerable libbiosig library.
• Phishing: An attacker can send a malicious MFER file via email or other communication channels, enticing the victim to open the file with a vulnerable application.

Exploitation Methods:

• Buffer Overflow: The vulnerability occurs when the len parameter exceeds the buffer size of v, which is only 17 bytes. This can lead to overwriting adjacent memory, potentially allowing an attacker to inject and execute arbitrary code.
• Code Execution: By carefully crafting the payload, an attacker can manipulate the stack to execute malicious code, gaining control over the affected system.

3. Affected Systems and Software Versions

Affected Software:

• The Biosig Project libbiosig version 3.9.0
• The Biosig Project libbiosig Master Branch (commit 35a819fa)

Affected Systems:

• Any system or application that uses the vulnerable versions of libbiosig to process MFER files. This includes but is not limited to:
  • Medical and biomedical research software
  • Data analysis tools that handle biosignal data
  • Any custom applications built on top of libbiosig

4. Recommended Mitigation Strategies

Immediate Actions:

• Patching: Apply the latest patches or updates provided by The Biosig Project to mitigate the vulnerability.
• Input Validation: Implement strict input validation to ensure that the len parameter does not exceed the buffer size.
• File Sanitization: Use file sanitization techniques to detect and reject malicious MFER files before processing.

Long-Term Strategies:

• Code Review: Conduct a thorough code review to identify and fix similar vulnerabilities in other parts of the codebase.
• Security Training: Educate developers on secure coding practices to prevent future buffer overflow vulnerabilities.
• Regular Updates: Ensure that all software dependencies are regularly updated to the latest versions.

5. Impact on Cybersecurity Landscape

Implications:

• Widespread Impact: Given the critical nature of the vulnerability, it poses a significant risk to systems and applications that rely on libbiosig for processing biosignal data.
• Potential for Exploitation: The high CVSS score indicates a high likelihood of exploitation, making it a prime target for attackers.
• Industry-Specific Risks: The vulnerability is particularly concerning for the medical and biomedical research fields, where data integrity and security are paramount.

6. Technical Details for Security Professionals

Vulnerable Code Snippet:

else if (tag==3) {
    // character code
    char v[17];  // [1]
    if (len>16) fprintf(stderr,"Warning MFER tag2 incorrect length %i>16\n",len);
    curPos += ifread(&v,1,len,hdr);
    v[len]  = 0;

Technical Analysis:

• Buffer Size: The buffer v is declared with a size of 17 bytes.
• Length Check: The code checks if len is greater than 16 and issues a warning, but it does not prevent the overflow.
• Memory Overwrite: The ifread function reads len bytes into v, potentially overwriting adjacent memory if len exceeds 16.

Mitigation Code Example:

else if (tag==3) {
    // character code
    char v[17];  // [1]
    if (len > 16) {
        fprintf(stderr,"Warning MFER tag2 incorrect length %i>16\n",len);
        // Handle error or return
        return -1;
    }
    curPos += ifread(&v,1,len,hdr);
    v[len]  = 0;

Conclusion: CVE-2025-54481 is a critical vulnerability that requires immediate attention. Organizations using the affected versions of libbiosig should prioritize patching and implementing robust input validation to mitigate the risk of exploitation. The cybersecurity community should remain vigilant and proactive in addressing similar vulnerabilities to protect sensitive data and systems.