A Comprehensive Study of DNS-over-HTTPS Downgrade Attack
summary
Examines DNS-over-HTTPS (DoH) downgrade attacks against six web browsers by analyzing four practical attack vectors that allow DoH to fall back to plain DNS. Shows that Opportunistic Privacy profiles (enabled by default) enable all tested browser/vector combinations to be downgraded, that browsers do not notify users when DoH is lost and some take long to recover, and proposes countermeasures and standards/implementation discussions to address the issue.
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chapters (11)
- 0:00Intro
- 0:23DNS Privacy
- 1:00DOH Service Support
- 1:27DNS over HTTPS (DOH, RFC 8484)
- 2:25Downgrade in DNS-over-HTTPS
- 2:52Research Gaps
- 3:24Doh Resolution Process
- 5:15Downgrade Attack Method
- 6:45Experimental Setup
- 7:05Terminology
- 8:48Feedback after Disclosure
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