Caddy allows enumeration of Certificates and Hostnames
Low severity
GitHub Reviewed
Published
May 14, 2022
to the GitHub Advisory Database
•
Updated Apr 24, 2024
Description
Published by the National Vulnerability Database
Nov 10, 2018
Published to the GitHub Advisory Database
May 14, 2022
Reviewed
Apr 24, 2024
Last updated
Apr 24, 2024
Caddy through 0.11.0 sends incorrect certificates for certain invalid requests, making it easier for attackers to enumerate hostnames. Specifically, when unable to match a Host header with a vhost in its configuration, it serves the X.509 certificate for a randomly selected vhost in its configuration. Repeated requests (with a nonexistent hostname in the Host header) permit full enumeration of all certificates on the server. This generally permits an attacker to easily and accurately discover the existence of and relationships among hostnames that weren't meant to be public, though this information could likely have been discovered via other methods with additional effort.
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