F12: Failure of Success Criterion 2.2.5 due to having a session time limit without a mechanism for saving user's input and re-establishing that information upon re-authentication | WAI | W3C Skip to content

Technique F12:Failure of Success Criterion 2.2.5 due to having a session time limit without a mechanism for saving user's input and re-establishing that information upon re-authentication

About this Technique

This technique relates to 2.2.5: Re-authenticating (Failure).

This failure applies to sites that require user login to submit input and that terminate the session after a some period of inactivity.

Description

Web servers that require user authentication usually have a session mechanism in which a session times out after a period of inactivity from the user. This is sometimes done for security reasons, to protect users who are assumed to have left their computer exposed in a state where someone could do something harmful to them such as transfer bank funds or make an unauthorized purchase. Users with disabilities may actually still be working to complete the form as it may take them longer to complete the form than would normally be expected. Upon re-authentication, if the state of users' sessions are not restored, including all data that had been previously entered into the form, they will have to start over. And for these users, it is likely that the session will time out again before they can complete the form. This sets up a situation where a user who needs more time to complete the form can never complete it.

Examples

  • A user submits a form on an authenticated site after their login has expired. On submitting the form, they are prompted to log in again, and then taken to a general welcome page. The data is not processed and they must try again.
  • A user submits a form on an authenticated site after their login has expired. On submitting the form, they are prompted to log in again, and then taken back to the page they were on just before the login, which in this case contains the form they attempted to submit. However, the form is not populated with the data they just entered, and they must re-enter it.

Tests

Procedure

On a site where authentication is required, user input is collected, and which ends the user's session after a known period of inactivity:

  1. Provide user input as required but allow the session to time out, then submit the form.
  2. When requested, re-authenticate with the server.
  3. Determine if the function is performed using the previously submitted data.

Expected Results

  • If check #3 is false, the site fails the Success Criterion.
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