Brakeman is a static analysis tool which checks Rails applications for security vulnerabilities. It is effectively a type of linter, similar to govuk-lint. It is configured to run automatically as part of the CI build process of any Rails application.
Dealing with false positives
There will be times when Brakeman flags up false positives in your code. You should try to refactor the code to satisfy Brakeman in such a way that it would also pass a code review. There is no benefit to refactoring the code just for Brakeman, if the resulting code is harder to understand.
There is an example of refactoring the Content Store to satisfy Brakeman where the resulting code could be considered slightly less elegant, but still suitable without having to ignore the warning.
You should only ignore warnings when it’s not possible to refactor the code in a way that is both elegant and satisfies Brakeman. Brakeman provides a useful tool for ignoring warnings:
$ brakeman -I
It will help you decide what to do with each individual warning step by step.
If you do decide to ignore a warning, you must include a note outlining why it is a false positive and not a security vulnerability.