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LibbiosigApplication · Libbiosig Project

CVE-2025-54485

CRITICAL · 9.8 CVSS v3.1 Published 2025-08-25
Fix available
A fix is available. Upgrade to 3.9.1 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
A stack-based buffer overflow vulnerability exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa). A specially crafted MFER file can lead to arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.This vulnerability manifests on line 8785 of biosig.c on the current master branch (35a819fa), when the Tag is 8: else if (tag==8) { if (len>2) fprintf(stderr,"Warning MFER tag8 incorrect length %i>2\n",len); curPos += ifread(buf,1,len,hdr);

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 · high confidence

Stack-based buffer overflow in libbiosig's MFER parser at biosig.c:8785 when processing Tag 8. The len parameter from the MFER file is used directly as the size for reading into a fixed-size buffer without proper bounds validation—only a warning is printed when len>2 but the read still proceeds, enabling arbitrary code execution.

MitigationAdd proper bounds checking on the len parameter before the ifread() call to ensure it does not exceed the buffer size, or update to a patched version of libbiosig when available; consider disabling MFER parsing if not required.

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:< 3.9.1

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 if libbiosig is installed
    Check for the presence of libbiosig library files or headers on the system (e.g., look for libbiosig in library directories, or check for biosig-related packages/libraries)
    Affected if libbiosig is present on the system
  2. Determine the installed libbiosig version
    Query the installed libbiosig version through package manager, library versioning, or by inspecting compiled binaries that link against libbiosig; compare the version number to the affected range (versions prior to 3.9.1)
    Affected if The installed version is lower than 3.9.1
  3. Verify if MFER parsing support is enabled
    Inspect the libbiosig build configuration or runtime settings to determine whether MFER file format parsing is compiled in or enabled (check for MFER-related flags, modules, or configuration options)
    Affected if MFER parsing support is compiled into or enabled for the library
  4. Check for MFER file processing activity
    Monitor or inspect logs, file access patterns, or application behavior that processes MFER files (.mfer extension) through libbiosig
    Affected if MFER files are being parsed by libbiosig-based applications

The environment is affected if a libbiosig version prior to 3.9.1 is installed with MFER parsing enabled and actively processing MFER files.

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 3.9.1 or later
Fixed in 3.9.1
Interim mitigation

Add proper bounds checking on the len parameter before the ifread() call to ensure it does not exceed the buffer size, or update to a patched version of libbiosig when available; consider disabling MFER parsing if not required.

Recommended fix Moderate confidence

libbiosig 3.9.1

  1. Check current installed version of libbiosig (e.g., via package manager or build system)
  2. Obtain libbiosig version 3.9.1 from the official source (likely the Biosig Project repository or release page)
  3. Replace or update the existing libbiosig library binary/source with version 3.9.1
  4. Rebuild any applications that link against libbiosig to ensure they use the updated library
  5. Verify the new version is correctly installed and the application functions as expected

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

Fix this in Libbiosig Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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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-2025-54485 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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