You may notice several products, WSRR included, keep on asking you to accept an unknown SSL certificate when first connecting to some sites. This is usually because the site is using a self-signed certificate, where the site itself says it's ok to trust it. In other words, you have no other trust-able organization saying the site is valid. Would you take someone's word that they are trustworthy and won't steal all your money?
Now it's quite important to know that the site you connect to is using a self-signed certificate, in case you don't want to trust such a site. It may be that you know you are using self-signed, for example during development where you don't pay for a real certificate, so you view the self-signed certificate and accept it. You may check that the certificate is for the host you are connecting to, or created by your organization, or even that the hash is what you expect.
So you may view the self-signed certificate, hit accept and then continue onward accessing the site, never prompted to accept the certificate again because you have already accepted it, and the certificate does not change.
Of course, at the point when you view the certificate, someone may get in between you and the server you connect to, and present their own certificate (man-in-the-middle-attack), and maybe you accept it and maybe you notice something is amiss and you don't accept it. This is the only chance to do a man-in-the-middle attack, upon the initial connection.
But here is why you should expect to see that prompt to accept the certificate. What if the tool you are using just connected and didn't bother to ask you? You wouldn't know the site was using self-signed, or have any chance of spotting a man-in-the-middle attack. You would just sail off into the sunset, using a compromised site without any idea at all.
Now this is all very well, and you might not even notice when accepting some certificate that it may be compromised. But what happens if you connected to the real site first time, and then some time later you get prompted to accept another certificate, because now someone has intercepted your communications and is presenting their own certificate? Now with a prompt you get a chance to wonder why you are being prompted, what's happened on that site that used to work to make it suddenly be asking for another certificate to be accepted. Maybe something bad has happened and you should stop?
More dangerous then is a tool which does not even prompt when the certificate it was using suddenly changes, and the tool just automatically accepts the new certificate without even asking you. This means that you are vulnerable to a man-in-the-middle attack at any point, not just when first connecting to a site. That's far more dangerous.
This is why WSRR Studio asks you to accept certificates it does not trust, and if that certificate changes, it will ask you to accept the certificate again.
For more information about Man-in-the-middle attacks, see Wikipedia.
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