SSL-enabled websites and links
SSL handles communication between your server and the requesting browser. With SSL, the html that contains your page is sent over an encrypted channel to the browser. The browser then decodes the html and displays the content. Whether the html contains links to websites other than your own is absolutely nothing. ...
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If you are loading a section of a page from another site, such as an iframe, then the encrypted HTML that is sent to the browser has a link to that external content. If this external dose of content doesn't encrypt the content, it doesn't affect encrypted content from your site.
Be that as it may, this can lead to security problems. You have no control over what the external content is, it might just log all the users' cookies that can be used to steal passwords.
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