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LibbiosigApplication · Libbiosig Project

CVE-2025-54490

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 9090 of biosig.c on the current master branch (35a819fa), when the Tag is 64: else if (tag==64) //0x40 { // preamble char tmp[256]; // [1] curPos += ifread(tmp,1,len,hdr); In this case, the overflowed buffer is the newly-declared `tmp` \[1\] instead of `buf`. While `tmp` is larger than `buf`, having a size of 256 bytes, a stack overflow can still occur in cases where `len` is encoded using multiple octets and is greater than 256.

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

A stack-based buffer overflow exists in libbiosig's MFER file parsing. When parsing MFER files with tag value 64 (0x40), the code at line 9090 of biosig.c copies data into a 256-byte stack buffer `tmp` using a length value from the file without validating that the length doesn't exceed the buffer size. If an attacker provides an MFER file where `len` exceeds 256 bytes, the stack buffer overflows, potentially enabling arbitrary code execution.

MitigationDo not process untrusted MFER files with libbiosig until a patch is applied. The fix requires validating that the `len` parameter from the file does not exceed the 256-byte buffer size before copying data into `tmp`.

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 libbiosig installation and version
    Check for libbiosig library files and retrieve the installed version. Common locations include /usr/lib/, /usr/local/lib/, or within application bundles. Use commands like 'pkg-config --modversion biosig' or inspect the library binary metadata.
    Affected if libbiosig is installed and its version is below 3.9.1
  2. Confirm MFER file parsing support is enabled
    Verify that the libbiosig build includes MFER format support. Check build configuration files, or look for MFER-related symbols or modules within the library.
    Affected if MFER support is compiled into or loaded by libbiosig
  3. Detect MFER file processing activity
    Monitor or inspect for processes that parse MFER files. Check application logs, file access patterns, or configuration that specifies MFER as an input format.
    Affected if Applications or services process MFER files as input
  4. Identify applications using libbiosig
    Scan for executables or services that link to libbiosig. Use commands like 'ldd' on binaries or check dependency lists in application configurations.
    Affected if Applications dynamically or statically link to libbiosig and process MFER data

A user is affected if their environment has libbiosig version below 3.9.1 with MFER file 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

Do not process untrusted MFER files with libbiosig until a patch is applied. The fix requires validating that the `len` parameter from the file does not exceed the 256-byte buffer size before copying data into `tmp`.

Recommended fix High confidence

libbiosig 3.9.1

  1. 1. Identify all systems and applications that use libbiosig for MFER file parsing.
  2. 2. Check the currently installed version of libbiosig on each affected system using package manager or by querying the library version.
  3. 3. Obtain libbiosig version 3.9.1 or later from the official source (https://biosig.sourceforge.net/ or official distribution channels).
  4. 4. Upgrade libbiosig to version 3.9.1 or newer following the project's installation instructions.
  5. 5. Rebuild and redeploy any applications that statically link against libbiosig.
  6. 6. Verify the upgrade was successful by checking the installed version.
  7. 7. Test MFER file parsing functionality to ensure normal operation after the upgrade.

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

Fix this in Libbiosig Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
20.0 hours of engineering $3,440
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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-2025-54490 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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