<story><title>Calling time on DNSSEC: The costs exceed the benefits</title><url>https://www.mattb.nz/w/2023/06/02/calling-time-on-dnssec/</url></story><parent_chain></parent_chain><comment><author>peanut-walrus</author><text>Here&amp;#x27;s the full list of DNS attacks DNSSEC protects against:&lt;p&gt;&lt;pre&gt;&lt;code&gt;  * Resolver cache poisoning
  * MitM upstream from resolver
&lt;/code&gt;&lt;/pre&gt;
That&amp;#x27;s it. That is all that DNSSEC does. Meanwhile, here&amp;#x27;s some attacks or concerns that are actually seen in the real-world and which DNSSEC does nothing for:&lt;p&gt;&lt;pre&gt;&lt;code&gt;  * Passive data collection
  * Malicious DNS resolvers
  * Registrar account compromises
  * Local network MitM against endpoints
&lt;/code&gt;&lt;/pre&gt;
And these are the real-world attacks which are enabled or made worse by DNSSEC:&lt;p&gt;&lt;pre&gt;&lt;code&gt;  * DNS Amplification DDoS
  * DNS server denial of service (on-the-fly signing or validating signed responses adds non-trivial overhead)
  * Zone enumeration (NSEC and NSEC3 are hilarious)
  * DNS server compromise through RCE exploits (not exclusive to DNSSEC, but handling signed responses adds a lot of complexity to servers and almost all DNS RCE exploits we&amp;#x27;ve seen recently have been in the DNSSEC handling part)
&lt;/code&gt;&lt;/pre&gt;
Add to this the complexity of key handling and the risk of breaking your own zones and the calculation is pretty clear - on the whole, DNSSEC is actively making things worse and not providing a clear benefit for anyone.</text></comment>
<story><title>Calling time on DNSSEC: The costs exceed the benefits</title><url>https://www.mattb.nz/w/2023/06/02/calling-time-on-dnssec/</url></story><parent_chain></parent_chain><comment><author>thayne</author><text>There is one case where I think DNSSEC provides a lot of value: domain validation for the purpose of issuing a TLS certificate.&lt;p&gt;To get a DV certificate, the most common kind, you &lt;i&gt;just&lt;/i&gt; have to prove you own the domain. If someone can MitM the DNS request to verify domain ownership, then they can issue a certificate for your domain. Transperency logs help protect against this, as long as you are watching them, and notice the bad cert issued before too much damage is done. Granted, there isn&amp;#x27;t a big risk of MitM between the nameserver and the CA, hopefully with multiple locations. But a state actor might be able to do it.&lt;p&gt;Still, I&amp;#x27;m not sure that is worth the complexity of DNSSEC. Especially since you really only need signed records for specific records.</text></comment>