CNAME Uncloaking Tests

Test instructions: Visit this page on test-cname.brave.dev and confirm that the status of a CNAME cloaked network request is consistent with the following expected behavior:

Setup

Add the following line to brave://adblock:

||dev-pages.brave.software/static/images/test.jpg

A DoH pre-check will verify that test-cname.brave.dev CNAMEs to dev-pages.brave.software before enabling the test.

Expected behavior

  • Standard shields mode: request is allowed
  • Aggressive shields mode: request is blocked

Disabling conditions

Any of the following conditions should cause the request to be allowed. Network analysis should also reveal that no additional DNS queries are made alongside the request.

  • Shields down
  • #brave-adblock-cname-uncloaking feature flag disabled in brave://flags
  • Tor session
  • Proxy/VPN WebExtension installed and active

If this test page isn't working as expected, ping on #privacy channel.