Fix path traversal in CamaleonCmsAwsUploader and add regression coverage

Author: texpert

.github/copilot-instructions.md

@@ -0,0 +1 @@
+When running rspec tests, please ensure that the RAILS_ENV environment variable is always set to test. The command should be executed as RAILS_ENV=test bundle exec rspec.

app/uploaders/camaleon_cms_aws_uploader.rb

@@ -37,6 +37,8 @@ def objects(prefix = '/', sort = 'created_at')
   end
 
   def fetch_file(file_name)
+    return { error: 'Invalid file path' } unless valid_folder_path?(file_name)
+
     return file_name if file_exists?(file_name)
 
     return file_name if bucket.object(file_name).download_file(file_name) && file_exists?(file_name)
@@ -84,8 +86,9 @@ def file_parse(s3_file)
   #   - same_name: false => avoid to overwrite an existent file with same key and search for an available key
   #   - is_thumb: true => if this file is a thumbnail of an uploaded file
   def add_file(uploaded_io_or_file_path, key, args = {})
+    return { error: 'Invalid file path' } unless valid_folder_path?(key)
+
     args = { same_name: false, is_thumb: false }.merge(args)
-    res = nil
     key = "#{@aws_settings['inner_folder']}/#{key}" if @aws_settings['inner_folder'].present? && !args[:is_thumb]
     key = key.cama_fix_media_key
     key = search_new_key(key) unless args[:same_name]
@@ -117,6 +120,8 @@ def add_folder(key)
 
   # delete a folder in AWS with :key
   def delete_folder(key)
+    return { error: 'Invalid folder path' } unless valid_folder_path?(key)
+
     key = "#{@aws_settings['inner_folder']}/#{key}" if @aws_settings['inner_folder'].present?
     key = key.cama_fix_media_key
     bucket.objects(prefix: key.slice(1..-1) << '/').delete
@@ -125,6 +130,8 @@ def delete_folder(key)
 
   # delete a file in AWS with :key
   def delete_file(key)
+    return { error: 'Invalid file path' } unless valid_folder_path?(key)
+
     key = "#{@aws_settings['inner_folder']}/#{key}" if @aws_settings['inner_folder'].present?
     key = key.cama_fix_media_key
     begin

spec/uploaders/aws_uploader_spec.rb

@@ -0,0 +1,114 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe CamaleonCmsAwsUploader do
+  init_site
+
+  let(:current_site) { Cama::Site.first.decorate }
+  let(:hook_instance) { instance_double('UploaderHookInstance', hooks_run: nil) }
+  let(:uploader) { described_class.new({ current_site: current_site, aws_settings: {} }, hook_instance) }
+  let(:bucket) { instance_double('Aws::S3::Bucket') }
+
+  before { allow(uploader).to receive(:bucket).and_return(bucket) }
+
+  context 'with an invalid path containing path traversal characters' do
+    describe '#add_file' do
+      it 'returns an error' do
+        expect(bucket).not_to receive(:object)
+
+        expect(uploader.add_file('/tmp/test.png', '../tmp/test.png')).to eql(error: 'Invalid file path')
+      end
+    end
+
+    describe '#delete_folder' do
+      it 'returns an error' do
+        expect(bucket).not_to receive(:objects)
+
+        expect(uploader.delete_folder('../tmp')).to eql(error: 'Invalid folder path')
+      end
+    end
+
+    describe '#delete_file' do
+      it 'returns an error' do
+        expect(bucket).not_to receive(:object)
+        expect(hook_instance).not_to receive(:hooks_run)
+
+        expect(uploader.delete_file('../tmp/test.png')).to eql(error: 'Invalid file path')
+      end
+    end
+  end
+
+  context 'with an invalid URI-like path' do
+    describe '#add_file' do
+      it 'returns an error' do
+        expect(bucket).not_to receive(:object)
+
+        expect(uploader.add_file('/tmp/test.png', 'file:///tmp/test.png')).to eql(error: 'Invalid file path')
+      end
+    end
+
+    describe '#delete_folder' do
+      it 'returns an error' do
+        expect(bucket).not_to receive(:objects)
+
+        expect(uploader.delete_folder('s3://bucket/folder')).to eql(error: 'Invalid folder path')
+      end
+    end
+
+    describe '#delete_file' do
+      it 'returns an error' do
+        expect(bucket).not_to receive(:object)
+        expect(hook_instance).not_to receive(:hooks_run)
+
+        expect(uploader.delete_file('https://example.com/file.txt')).to eql(error: 'Invalid file path')
+      end
+    end
+  end
+
+  context 'with a valid file path' do
+    describe '#add_file' do
+      let(:s3_file) { instance_double('Aws::S3::Object') }
+      let(:parsed_file) do
+        {
+          'name' => 'test.png',
+          'folder_path' => '/safe',
+          'url' => 'https://cdn.example.com/safe/test.png',
+          'is_folder' => false,
+          'file_size' => 123.45,
+          'thumb' => '/safe/thumb/test-png.png',
+          'file_type' => 'image',
+          'created_at' => '2026-03-09T00:00:00Z',
+          'dimension' => '100x100',
+          'key' => '/safe/test.png'
+        }
+      end
+
+      before do
+        allow(bucket).to receive(:object).and_return(s3_file)
+        allow(s3_file).to receive(:upload_file).and_return(true)
+        allow(uploader).to receive(:search_new_key).and_return('/safe/test.png')
+        allow(uploader).to receive(:file_parse).with(s3_file).and_return(parsed_file)
+        allow(uploader).to receive(:cache_item).with(parsed_file).and_return(parsed_file)
+      end
+
+      it 'uploads the file and returns cached metadata' do
+        file_path = "#{CAMALEON_CMS_ROOT}/spec/support/fixtures/rails.png"
+        expect(hook_instance).to receive(:hooks_run).with(
+          'uploader_aws_before_upload',
+          hash_including(
+            file: file_path, key: '/safe/test.png', args: hash_including(same_name: false, is_thumb: false)
+          )
+        )
+
+        result = uploader.add_file(file_path, 'safe/test.png')
+
+        expect(bucket).to have_received(:object).with('safe/test.png')
+        expect(s3_file).to have_received(:upload_file).with(
+          file_path, { acl: 'public-read' }
+        )
+        expect(result).to eql(parsed_file)
+      end
+    end
+  end
+end