CPE-Mapper

CPE-mapper is a CLI tool and JSON-based database designed to accurately map software package names to their corresponding CPEs (Common Platform Enumerations).

Its main goal is to improve vulnerability identification in cases where standard package names fail to match known CPEs.

Highlights

• 📦 Easy to install and easy to use
• ⚡ Lightweight and fast
• 🔒 Security-focused with evidence-backed mappings
• 🔍 Improved vulnerability detection through custom CPE mappings
• ✨ Compatible CycloneDX JSON and SPDX JSON
• 🧩 Roadmap includes XML support, custom user mappings database and deploying it as a server

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How does it work

CPE-mapper is a rather simple tool.

It does not analyze your source code or repository to guess which dependencies correspond to which CPEs. Instead, it relies on a JSON mapping file (our CPE database) that explicitly defines, for each package name, the corresponding CPE.

We use the NVD (National Vulnerability Database) as a reference to determine which CPE is used for a specific piece of software, and we manually link them together.

For example, NVD reports vulnerabilities for Apache Tomcat using the CPE:

cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*

However, this CPE cannot be directly derived from the Java package name org.apache.tomcat.embed:tomcat-embed-core.

To solve this, CPE-mapper maintains a mapping in its database so that when it processes a BOM file, if it finds the package org.apache.tomcat.embed:tomcat-embed-core, it automatically adds the corresponding CPE cpe:2.3:a:apache:tomcat:<your_package_version>:*:*:*:*:*:*:* to the output.

False positives

CPE-mapper may report false positives, due to how the NVD assigns CPEs to CVEs.

Let’s take Log4j as an example: all CVEs related to Log4j are associated with the following CPE:

cpe:2.3:a:apache:log4j:<log4j_version>:*:*:*:*:*:*:*

This way of tagging vulnerabilities does not take into account the different modules that make up Log4j, such as log4j-core, log4j-api, log4j-web, or log4j-slf4j-impl.

In other words, the NVD does not distinguish between the different packages that compose a piece of software; it treats the entire project as a single entity.

As a result, we decided to associate CPEs with the core package of each software (e.g., log4j-core, tomcat-embed-core, logback-core...), since these core modules are used or implemented by all their derived packages (for example in Log4j: log4j-api, log4j-web...).

This ensures that you are notified whenever a new CVE is published for the software as a whole.

While this approach may generate false positives (for instance, some CVEs might affect a derived package you don’t actually use), it provides the safest coverage to ensure you don’t miss any relevant vulnerabilities.

Getting Started

You can use CPE-Mapper in your CI/CD or in your local machine.

Installing

You can install CPE-mapper in several ways:

1. From npm.

npm install -g @bastienbyra/cpe-mapper

# You can then run it using `cpe-mapper`

2. Through our Docker image.

docker run -v path/to/your/bom/folder:/data --rm ghcr.io/bastienbyra/cpe-mapper:latest apply -i /data/bom.json -o /data/mapped_bom.json

Commands

Apply

Usage: cpe-mapper apply [options]

Apply CPE mappings to a BOM file

Options:
  -i, --input-file <file>   Input BOM file (JSON)
  -o, --output-file <file>  Output mapped BOM file
  -u, --no-update           Disable updating the CPE Mapping database
  --override-cpe            Override BOM CPEs with mapped values from our database (CycloneDX only)
  -v, --verbose             Enable verbose logging
  -h, --help                display help for command

Example

Apply CPE-mapper database mappings to a BOM file

cpe-mapper apply -i input-bom.json -o output-bom.json

Apply CPE-mapper database mappings to a BOM file, overwriting the existing CPEs in the input file.

cpe-mapper apply -i input-bom.json -o output-bom.json --override-cpe

Note:

The --override-cpe flag is intended only for CycloneDX files, as SPDX supports multiple externalRefs (and therefore multiple CPE mappings), whereas CycloneDX files can have only one

Update

Usage: cpe-mapper update [options]

Update the CPE mappings database

Options:
  -h, --help  display help for command

Example

Check if the database has updates and apply them.

cpe-mapper update

GitHub Actions

CPE-Mapper provides a GitHub Action that can be used to apply CPE mappings to your BOM files.

Configuration

Note: You can find the configuration in the action.yml file.

- uses: BastienBYRA/[email protected]
  with:
    # The input BOM file to which CPE-Mapper applies the mapping.
    # Required. Example: testdata/bom.test.json
    input-file: ''

    # The name of the output BOM file.
    # Required. Example: testdata/bom.result.json
    output-file: ''

    # Whether to override existing CPEs in the input BOM file (CycloneDX only). Choices are `true` or `false`.
    # Optional. Default: false
    override-cpe: false

    # Enable verbose mode. Choices are `true` or `false`.
    # Optional. Default: false
    verbose: false

Tip: It is recommended to use a release/tag version instead of main to make the workflow immutable.

Usage

name: Security CI

on: [push]

jobs:
  apply-cpe:
    name: Apply CPE to BOM file
    runs-on: ubuntu-latest
    steps:
      - name: Apply CPE mapping
        uses: BastienBYRA/CPE-Mapper@main
        with:
          input-file: testdata/bom.test.json
          output-file: testdata/bom.result.json

      # Archive the output BOM file as an artifact
      - name: Archive artifacts
        uses: actions/upload-artifact@v4
        with:
          name: mapped-sbom
          path: testdata/bom.result.json
          retention-days: 1

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Contributing

If you would like to contribute to this project, whether by reporting issues, proposing new ideas, developing features, or adding entries to the CPE database, please see the CONTRIBUTING guide for details.

Roadmap

The ROADMAP lists all the tasks planned for the future.