No, there is not a specific website, or dedicated mailing list.
The procedure for filing bug reports is outlined at URL:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/template.htm
Substitute the email address of the current Convenor, on the page:
http://www.open-std.org/jtc1/sc22/wg14/www/contacts
as necessary.
While not specified, an email subject line should include the phrase:
Draft C{nn} Defect: {title}
where {nn} is the version, 99, 11, 17, or 2x being commented on and a TC reference if needed, e.g. C99TC2, and {title} is a suggested value for the Subject: line of a Defect Report; to differentiate it from other types of email that box might get.
The URLs above are valid as of this writing as publicly accessible. Whether WG14 keeps them accessible is not in my control. Ymmv applies, in other words.