I'd appreciate if someone could shed some lights on the subject findings.
Is this a security problem having
bank.com appearing on the SAN?
Hostname was discovered in the Subject Alternative Name (SAN) of the certificate presented by the service.
It sounds like you got a report with "SSL Certificate Subject Alternative Name Information Disclosure" in big scary letters and you're not sure what to do about it.
This is one of those things where 90% of the time it's not a problem and you can mark it as a false positive.
Here's how certificates and SANs work: when I tell my browser to connect to
security.stackexchange.com, my browser expects the server to present a certificate containing this domain in a SAN. If you click the padlock, you'll see that the first SAN is
DNS Name=*.stackexchange.com so we're good. On the surface there's nothing wrong with this.
The reason tools report "Information Disclosure" warnings for certificates is that sometimes people put more information than they should in a certificate. For example if the certificate listed the hostnames of each loadbalancer, that would be a problem because you're telling attackers what individual machines are on your network.
Bottom line: you'll need to look at what information is being "disclosed" in the SAN and ask yourself "Is this public information that someone needs to know in order to use our site, or does it give away secret information about our internal network structure?"