Potential fix for code scanning alert no. 3: Workflow does not contain permissions

[jonathanpmoraes]

Potential fix for https://github.com/nubank/NuMarquez/security/code-scanning/3

In general, the fix is to explicitly define a permissions block in the workflow (either at the root level or within the build job) to restrict the GITHUB_TOKEN to the least privileges needed. This documents the intended access and prevents accidental escalation if repository/organization defaults change.

For this workflow, the steps only read repository contents and metadata: actions/checkout reads the repo, actions/setup-python configures the environment, and jitterbit/get-changed-files uses the token to list changed files. No step writes to the repository, issues, or pull requests. The best minimal permission is therefore contents: read. To keep the change small and not alter existing functionality, add a permissions block under the build job (where CodeQL flagged the issue), e.g.:

jobs:
  build:
    name: Check for Headers
    runs-on: ubuntu-latest
    permissions:
      contents: read
    steps:
      ...

This modification should be added in .github/workflows/headerchecker.yml between runs-on: ubuntu-latest and steps:. No additional imports, methods, or definitions are needed; GitHub Actions interprets the permissions key natively.

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