Dormant Non-Privileged User

This IoE cannot work without a Microsoft Entra ID P1 or P2 license due to data availability restrictions by Microsoft.

A dormant user is a user account that has remained inactive by not completing any successful sign-in for a specified period (90 days by default, customizable through an option).

Dormant users could introduce the following security risks and operational complications:

• As potential targets for attackers if these accounts have weak or unchanged passwords, facilitating a compromise. For example, a CISA alert reported that:

  campaigns have also targeted dormant accounts belonging to users who no longer work at a victim organization but whose accounts remain on the system

• An increase in the Entra tenant's attack surface by creating potential vulnerabilities. For example, the same CISA alert reported that:

  Following an enforced password reset for all users during an incident, SVR actors have also been observed logging into inactive accounts and following instructions to reset the password. This has allowed the actor to regain access following incident response eviction activities.

• Access to individuals who no longer require it, such as former employees or interns.

• Waste of resources such as licenses. Regular identification, deactivation, or removal of dormant users allow organizations to optimize resource allocation and save unnecessary costs.

Also, consider the related IoE "Never Used Non-Privileged User" which identifies all users that were pre-created but never used. See also the related IOE, "Dormant Privileged User", for privileged users.

Note:

1. This IoE relies on the lastSuccessfulSignInDateTime property within the signInActivity property of User objects. Its advantage lies in reporting only successful sign-ins to avoid disruption arising from failed attempts, unlike the property lastSignInDateTime. The lastSuccessfulSignInDateTime property became available in December 2023.
2. To access the signInActivity resource type, you need a Microsoft Entra ID P1 or P2 license for each tenant. Otherwise, this IoE cannot detect dormant users and therefore skips the entire analysis.
3. Since this property remains unfilled for users who never signed in or last signed in before December 2023, the required data to evaluate the interval is unavailable. Consequently, Tenable Identity Exposure cannot properly detect the last sign-in date, potentially resulting in false positives.

Tenable recommends that you regularly review and disable or delete dormant users. After identifying them, take the following actions:

1. Disable them.
2. Wait a few months.
3. After this delay, if there are no reported issues, and if the organization's information security policy allows, proceed to delete them.

Name: Dormant Non-Privileged User

Codename: DORMANT-NON-PRIVILEGED-USER

Severity: Low

Type: Microsoft Entra ID Indicator of Exposure