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LibbiosigApplication · Libbiosig Project

CVE-2025-66047

CRITICAL · 9.8 CVSS v3.1 Published 2025-12-11
Fix available
A fix is available. Upgrade to 3.9.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Several stack-based buffer overflow vulnerabilities exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.1. A specially crafted MFER file can lead to arbitrary code execution. An attacker can provide a malicious file to trigger these vulnerabilities.When Tag is 131

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Stack-based buffer overflow vulnerabilities exist in the MFER file parsing code of libbiosig 3.9.1. When processing MFER files with specific Tag values (specifically Tag 131), the parser does not properly validate input sizes before copying data into fixed-size stack buffers, allowing controlled overflow and potential arbitrary code execution.

MitigationUpdate to the latest version of libbiosig that addresses these vulnerabilities. If no patched version is available, implement strict bounds checking in all MFER parsing routines, particularly for Tag 131 handling, and consider input validation/sanitization before passing files to the library.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
LibbiosigApplication
Affected:< 3.9.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed libbiosig version
    Run 'pkg-config --modversion libbiosig' or check the library file version attribute (e.g., 'strings libbiosig.so | grep -i version' or examine the shared object metadata)
    Affected if The version is 3.9.1 or any version lower than 3.9.2
  2. Verify MFER parsing support is compiled into the library
    Check the library binary for MFER-related symbols: 'nm -D libbiosig.so | grep -i mfer' or 'objdump -T libbiosig.so | grep -i mfer'
    Affected if MFER parsing symbols are present, indicating the vulnerable code path exists in the compiled library
  3. Confirm application usage of libbiosig for MFER file input
    Review application code or runtime behavior to see if MFER files are processed; check for file type detection logic or calls to biosig functions with MFER-formatted input
    Affected if The application loads and parses MFER files using libbiosig
  4. Inspect for custom MFER Tag 131 handling if using custom parsers
    Search source code for 'Tag 131' or '0x83' references in any MFER parsing implementations that use libbiosig
    Affected if Custom code processes Tag 131 values from MFER files through libbiosig

You are affected if libbiosig version is below 3.9.2 AND your system uses libbiosig to parse MFER files, particularly those containing Tag 131 data.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.9.2 or later
Fixed in 3.9.2
Interim mitigation

Update to the latest version of libbiosig that addresses these vulnerabilities. If no patched version is available, implement strict bounds checking in all MFER parsing routines, particularly for Tag 131 handling, and consider input validation/sanitization before passing files to the library.

Recommended fix Moderate confidence

libbiosig 3.9.2

  1. Identify all systems and applications using libbiosig library
  2. Check current installed version of libbiosig (likely via package manager or library inspection)
  3. Download libbiosig version 3.9.2 or later from the official Biosig Project source (https://biosig.sourceforge.net/)
  4. Replace the vulnerable libbiosig library file with the updated version
  5. Rebuild or recompile any applications that link against libbiosig to ensure they use the new library
  6. Restart any services or applications using libbiosig to load the updated library
  7. Verify the upgrade was successful by checking the new library version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Libbiosig Scoped from the published advisory
  • Consultation6.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA6.0 h
40.0 hours of engineering $6,960
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $11,136.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-66047 in production — separate from our analysis above.

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  • Version or environment caveats, and links to real fixes
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