Self-service password reset
Self-service password reset is defined as any process or technology that allows users who have either forgotten their password or triggered an intruder lockout to authenticate with an alternate factor, and repair their own problem, without calling the help desk. It is a common feature in Identity management software and often also includes a password synchronization capability.
Typically users who have forgotten their password launch a self-service application from an extension to their workstation login prompt, using their own or another user's web browser, or through a telephone call. Users establish their identity, without using their forgotten or disabled password, by answering a series of personal questions, using a hardware authentication token, responding to a password notification e-mail or, less often, by providing a biometric sample. Users can then either specify a new, unlocked password, or ask that a randomly generated one be provided.
Self-service password reset expedites problem resolution for users "after the fact," and thus reduces help desk call volume. It can also be used to ensure that password problems are only resolved after adequate user authentication, eliminating an important weakness of many help desks: Social engineering attacks, where an intruder calls the help desk, pretends to be the intended victim user, claims that he has forgotten his password, and asks for a new password.
Vulnerability
On the other hand, self-service password reset that relies solely on answers to personal questions can introduce new vulnerabilities, since the answers to such questions can often be obtained by social engineering, phishing techniques or simple research. While users are frequently reminded never to reveal their password, they are less likely to treat as sensitive the answers to many commonly used security questions, such as pet names, place of birth or favorite movie. Much of this information may be publicly available on some users' personal home pages. Other answers can be elicited by someone pretending to conduct an opinion survey or offering a free dating service. Since many organizations have standard ways of determining login names from real names, an attacker who knows the names of several employees at such an organization can choose one whose security answers are most readily obtained.