Project: WASC Threat Classification

Threat Type: Weakness

Reference ID: WASC-49


Insufficient Password Recovery

Insufficient Password Recovery is when a web site permits an attacker to illegally obtain, change or recover another user’s password. Conventional web site authentication methods require users to select and remember a password or passphrase. The user should be the only person that knows the password and it must be remembered precisely. As time passes, a user’s ability to remember a password fades. The matter is further complicated when the average user visits 20 sites requiring them to supply a password.  (RSA Survey: Thus, password recovery is an important part in servicing online users.


Examples of automated password recovery processes include requiring the user to answer a “secret question” defined as part of the user registration process. This question can either be selected from a list of canned questions or supplied by the user. Another mechanism in use is having the user provide a “hint” during registration that will help the user remember his password. Other mechanisms require the user to provide several pieces of personal data such as their social security number, home address, zip code etc. to validate their identity. After the user has proven who they are, the recovery system will display or e-mail them a new password.


A web site is considered to have Insufficient Password Recovery when an attacker is able to foil the recovery mechanism being used. This happens when the information required to validate a user’s identity for recovery is either easily guessed or can be circumvented. Password recovery systems may be compromised through the use of brute force attacks, inherent system weaknesses, or easily guessed secret questions.