Resetting ASP.NET password – security issues

It depends on the the level of security you are aiming for, support costs and usability concerns.

Emailing a password reset link is the preferred approach for a number of reasons:

• Support Costs - This is the biggest factor from a business perspective. Users often forget even their password hints or use a fake mailing address or forget their user name. All of these are legitimate concerns for which you might get support requests. This in turn creates another issue, you have to establish the legitimacy of the user by asking them about recent account activity and what not. If you don't provide that level of support a lot of novice users will be disappointed. Emailing a password reset link mitigates these concerns because the users typically have one or two email addresses and they can easily recover their username/password by providing their email address.

• Security Concerns - This is the biggest factor from a technical perspective. There are various concerns here which you have to weigh. A compromised email account means the hacker can go to access all of the users' services which allow a password reset link to be emailed. You can settle for middle ground which is to email a password reset link to the user which in turn asks the user a password hint question after which it allows them to reset their password. Again, you should never expose the user's password in any medium. In fact, if you have the capability to show them their password your system is already insecure because it implies you are not storing them using a secure hash like SHA-1 and a developer in your company can get at everyone's password.

• Usability - This is the biggest factor from the user perspective. Emailing a password reset link requires the user go and check their email address which can means the time to achieve the task can go up to 2 or even 3 minutes. However, I would think that this is not a big deal. Most users don't seem to mind this because they feel they are at fault and this is a security measure in their best interest. I am only hypothesizing from personal experience and users in general might feel differently. I would put security as a higher priority than the user experience because users will rarely if ever need to retrieve their passwords (user has not logged in for a long time and forgot his password; user had saved his password in the browser which was reinstalled and some other edge cases).

What I ended up doing was the following

public string ResetPassword(string email)
        {
            var m_userName = Membership.GetUserNameByEmail(email);
            var m_user = Membership.GetUser(m_userName);
            return m_user.ResetPassword();
        }

then I added a new method to use this value to change the password

public bool ChangeLostPassword(string email, string newPassword)
    {
        var resetPassword = ResetPassword(email);
        var currentUser = Membership.GetUser(Membership.GetUserNameByEmail(email), true);
        return currentUser.ChangePassword(resetPassword, newPassword);

    }