Should a Website Show if an Email Exists or Not?
When a user requests a password reset on a website, should the website show if the entered email exists in their database or not? This question raises important security concerns that website owners need to consider.
The main problem with disclosing the existence or non-existence of email addresses is that it can provide valuable information to attackers. For example, if an attacker finds out that a specific email address is registered on a website, they can use this information to target the individual. This can be especially problematic for sensitive websites, as seen in the case of the Ashley Madison data breach.
Even for non-sensitive websites, disclosing email existence can still be useful for attackers. They can use this information to identify potential targets for phishing attacks or other malicious activities.
Considering these risks, it is recommended to use a generic message when handling password reset requests. Instead of explicitly stating whether the email exists or not, the website can provide a generic error message or simply claim that a password reset email has been sent, without confirming the existence of the email address.
It is important to note that if you choose to prevent disclosure during password reset, you should also apply the same principle during the registration process. However, it is worth considering that preventing disclosure during registration can potentially create usability issues, so the advantages and disadvantages need to be carefully weighed.