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thewisenerd/az-cdn-domain-fronting.md

Created May 1, 2023 14:17
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az-cdn-domain-fronting.md
  • DONE Domain Fronting to be blocked on Azure
    • HN
    • Azure
    • two https domains resolve to the same IP address
      • eg., (search for site:azureedge.net)
        • tmgpulse.azureedge.net
        • goodie.azureedge.net
      • an SSL request contains of two parts
        • SSL headers which contain "SNI"/server name indicator
        • encrypted HTTP content
      • if the content of the SNI and Host header of the HTTP content do not match
      • architecturally, this seems like
        • azure uses SNI for "nothing"
        • post termination, azure uses Host header for content delivery
      • this means, if a "firewall" wants to block "https://badwebsite.azureedge.net", a bad actor can get around this by
      • and hope azure serves the request
      • this can be used to get around firewalls only doing SNI inspection which would pose a problem for corporate environments and state actors (?)
      • on a similar note,
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