this post was submitted on 04 Dec 2024
25 points (100.0% liked)

Cybersecurity

5922 readers
240 users here now

c/cybersecurity is a community centered on the cybersecurity and information security profession. You can come here to discuss news, post something interesting, or just chat with others.

THE RULES

Instance Rules

Community Rules

If you ask someone to hack your "friends" socials you're just going to get banned so don't do that.

Learn about hacking

Hack the Box

Try Hack Me

Pico Capture the flag

Other security-related communities [email protected] [email protected] [email protected] [email protected] [email protected]

Notable mention to [email protected]

founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 4 points 1 month ago (1 children)

Ahh that makes more sense, especially if people aren't using the cf origin certs. I'd expect SNI to prevent this on newer systems though, unless it's the default cert on the ip.

[–] [email protected] 4 points 1 month ago

From the article:

The TLS-SNI header is used by CDN servers to route requests based on the Server Name in the header. However, a typical front end server, or even a load balancer (LB), belongs to a single app or organization, and does not typically need to handle the SNI header. The easy and reasonable way to configure TLS certificates on such a server, is to either:
 Serve all requests with a single TLS certificate that has SANs (Subject Alternative Names) for all the domains that are used Have multiple certificates, chosen according to SNI, with one of them as the default. In both of these common cases, sending a HTTPS request directly to the IP of a front end server, without any SNI, will present us with a default server certificate. This certificate will reveal what domains are being served by this server.

So apparently the real issue is that people aren't using SNI correctly.