How to Fix Sobelow Traversal.FileModule: Directory Traversal in `File.write`

Questions / Help
1

I use File.write(path) several times in my code and when I scan it by using Sobelow, it keeps raising Traversal.FileModule: Directory Traversal in File.write - Low Confidence.

Is there any appropriate way to fix it? Thank you in advance.

2

Try using the File.write! version:

unless File.exists?(destination) do
  File.mkdir_p(Path.dirname(destination))
end

File.write!(destination, module)
3

How to you compose the paths? Traversal vulnerabilities are about users being able to use paths to gain access to files they shouldn’t have access to (e.g. using /../ or ~/.)