&gt; But a the OP pointed-out, if a site using LE is compromised then the attacker has basically an infinite duration of valid certs, because they are automatically renewed.<p>As zeendo mentions, this is only true while the attacker can continue to provide proof that they control the site in question.<p>&gt; There is no manual challenge to receive a new cert.<p>You&#x27;re talking about a server on which an attacker has the ability to<p>* Read the server&#x27;s ACME private key<p>And one or more of<p>* Add new documents to [scheme]:&#x2F;&#x2F;[domain]&#x2F;.well-known&#x2F;acme-challenge&#x2F;<p>* Stand up a HTTPS server at the domain for which a key is being requested that responds with LE-provided data using a LE-provided temporary key.<p>* Sign challenge information using a previously issued private key.<p>* Add a TXT record for the domain in question containing data specified by the LE server.<p>This requires a server to be pretty <i>thoroughly</i> pwnt.<p>What&#x27;s more, even though cert revocation works poorly in the real world, the LE servers almost certainly respond correctly to cert revocation requests. So, if a server operator notices that his box has been pwnt, he can revoke the certs that were issued during the time, closing the &quot;Sign challenge info using a previously issued LE key&quot; barn door for good. (Or until his machine gets pwnt again.)<p>Frankly, I think that OP hasn&#x27;t actually had a good look at how the LE software works, or the design of ACME.