EUVD-2025-25672

Comprehensive Technical Analysis of EUVD-2025-25672

1. Vulnerability Assessment and Severity Evaluation

The vulnerability EUVD-2025-25672 is a stack-based buffer overflow in the MFER parsing functionality of The Biosig Project's libbiosig library, versions 3.9.0 and the Master Branch (35a819fa). This vulnerability allows an attacker to execute arbitrary code by providing a specially crafted MFER file. The severity of this vulnerability is rated with a CVSS Base Score of 9.8, indicating a critical risk. The CVSS vector (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) highlights the following characteristics:

• Attack Vector (AV): Network (N) - The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low (L) - The attack requires minimal skill or resources to exploit.
• Privileges Required (PR): None (N) - No special privileges are needed to exploit the vulnerability.
• User Interaction (UI): None (N) - No user interaction is required for the attack to succeed.
• Scope (S): Unchanged (U) - The vulnerability does not change the security scope.
• Confidentiality (C): High (H) - The vulnerability can lead to a complete breach of confidentiality.
• Integrity (I): High (H) - The vulnerability can lead to a complete breach of integrity.
• Availability (A): High (H) - The vulnerability can lead to a complete breach of availability.

2. Potential Attack Vectors and Exploitation Methods

The primary attack vector involves providing a maliciously crafted MFER file to the libbiosig library for parsing. This can be achieved through various means, such as:

• Phishing Attacks: Sending the malicious file via email or other communication channels to unsuspecting users.
• Web-Based Attacks: Hosting the malicious file on a website and enticing users to download it.
• Supply Chain Attacks: Compromising a legitimate software distribution channel to include the malicious file.

Exploitation methods include:

• Buffer Overflow: Crafting an MFER file that overflows the buffer when parsed, leading to arbitrary code execution.
• Memory Corruption: Manipulating the memory layout to inject and execute malicious code.

3. Affected Systems and Software Versions

The vulnerability affects:

• libbiosig version 3.9.0
• libbiosig Master Branch (35a819fa)

Any system or application that uses these versions of the libbiosig library for MFER file parsing is at risk.

4. Recommended Mitigation Strategies

To mitigate the risk associated with this vulnerability, the following strategies are recommended:

• Patch Management: Immediately update to a patched version of libbiosig once available.
• Input Validation: Implement strict input validation for MFER files to prevent malicious files from being processed.
• Sandboxing: Run the libbiosig library in a sandboxed environment to limit the impact of any successful exploitation.
• Network Segmentation: Segregate critical systems from less secure networks to reduce the attack surface.
• User Education: Educate users about the risks of downloading and opening files from untrusted sources.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to the European cybersecurity landscape, particularly in sectors that rely on biomedical signal processing, such as healthcare and research institutions. The potential for arbitrary code execution can lead to data breaches, system compromises, and loss of sensitive information. The high severity score and the ease of exploitation make it a critical concern for organizations using the affected versions of libbiosig.

6. Technical Details for Security Professionals

The vulnerability is located on line 9191 of biosig.c in the current master branch (35a819fa), specifically when the tag is 65 (0x41: patient event). The code snippet below shows the vulnerable section:

else if (tag==65)     //0x41: patient event
{
    // event table

    curPos += ifread(buf,1,len,hdr);
}

The ifread function is used to read data into the buffer buf, but there is no boundary check to ensure that the buffer does not overflow. This lack of boundary checking allows an attacker to craft an MFER file that overflows the buffer, leading to arbitrary code execution.

References:

• Talos Intelligence Vulnerability Report

Aliases:

• CVE-2025-54491

Assigner:

• Talos

EPSS:

• N/A

ENISA ID Product:

• libbiosig Master Branch (35a819fa)
• libbiosig version 3.9.0

ENISA ID Vendor:

• The Biosig Project

By addressing this vulnerability promptly and implementing robust mitigation strategies, organizations can significantly reduce the risk of exploitation and protect their systems and data.