diff --git a/lib/freedom_patches/web_push_request.rb b/lib/freedom_patches/web_push_request.rb new file mode 100644 index 00000000000..ee6c23ce477 --- /dev/null +++ b/lib/freedom_patches/web_push_request.rb @@ -0,0 +1,27 @@ +# frozen_string_literal: true + +# This is a patch to avoid the direct use of `Net::HTTP` in the `webpush` gem and instead rely on `FinalDestination::HTTP` +# which protects us from DNS rebinding attacks as well as server side forgery requests. +# +# This patch is considered temporary until we can decide on a longer term solution. In the meantime, we need to patch +# the SSRF vulnerability being exposed by this gem. +module WebPushPatch + def perform + http = FinalDestination::HTTP.new(uri.host, uri.port, *proxy_options) + http.use_ssl = true + http.ssl_timeout = @options[:ssl_timeout] unless @options[:ssl_timeout].nil? + http.open_timeout = @options[:open_timeout] unless @options[:open_timeout].nil? + http.read_timeout = @options[:read_timeout] unless @options[:read_timeout].nil? + + req = FinalDestination::HTTP::Post.new(uri.request_uri, headers) + req.body = body + + resp = http.request(req) + verify_response(resp) + + resp + end +end + +klass = defined?(WebPush) ? WebPush : Webpush +klass::Request.prepend(WebPushPatch) diff --git a/spec/lib/freedom_patches/web_push_spec.rb b/spec/lib/freedom_patches/web_push_spec.rb new file mode 100644 index 00000000000..d5164258374 --- /dev/null +++ b/spec/lib/freedom_patches/web_push_spec.rb @@ -0,0 +1,60 @@ +# frozen_string_literal: true + +klass = defined?(WebPush) ? WebPush : Webpush + +RSpec.describe klass do + before do + FinalDestination::SSRFDetector.allow_ip_lookups_in_test! + WebMock.enable!(except: [:final_destination]) + end + + after do + WebMock.enable! + FinalDestination::SSRFDetector.disallow_ip_lookups_in_test! + end + + it "should filter endpoint hostname through our SSRF detector" do + klass::Request.any_instance.expects(:encrypt_payload) + klass::Request.any_instance.expects(:headers) + + stub_ip_lookup("example.com", %W[0.0.0.0]) + + expect do + klass.payload_send( + endpoint: "http://example.com", + message: "test", + p256dh: "somep256dh", + auth: "someauth", + vapid: { + subject: "someurl", + public_key: "somepublickey", + private_key: "someprivatekey", + }, + ) + end.to raise_error(FinalDestination::SSRFDetector::DisallowedIpError) + end + + it "should send the right request if endpoint hostname resolves to a public ip address" do + klass::Request.any_instance.expects(:encrypt_payload) + klass::Request.any_instance.expects(:headers) + + stub_ip_lookup("example.com", %W[52.125.123.12]) + + success = Class.new(StandardError) + TCPSocket.stubs(:open).with { |addr| "52.125.123.12" == addr }.once.raises(success) + + expect do + klass.payload_send( + endpoint: "http://example.com", + message: "test", + p256dh: "somep256dh", + auth: "someauth", + vapid: { + subject: "someurl", + public_key: "somepublickey", + private_key: "someprivatekey", + }, + ) + end.to raise_error(success) + end +end