This article will explain the most common causes of Active Directory Lockouts, and how to mitigate them. For information on managing your Active Directory account policies and changing settings, refer to our blog: How to Change Active Directory (AD) Lockout Policy.
What is Active Directory?
Active Directory account lockouts are a common issue that system administrators must deal with. Active Directory (AD) is a critical component of any IT infrastructure, allowing organizations to manage and control access to resources. It stores user accounts, computers, printers, and groups with a pre-defined permission policy. The main function of Active Directory is to handle security authentication across the domain, and it does this by only allowing authorized users to logon to their respective machines affiliated with the domain (usually work devices).
Why do Active Directory Account Lockouts Happen?
One of the most frustrating issues that IT professionals face is account lockouts. Account lockouts occur when a user enters incorrect login credentials multiple times, causing their account to be suspended. Active Directory has a threshold in place for user logon attempts. When that threshold has been reached, Active Directory locks out the user. The threshold can also have a duration limit, where it can lock the user account for a specified duration. Attacks such as brute force password guessing, password spraying, and Denial of Service (DoS) can all cause frequent lockouts. Ultimately, this affects the user’s ability to access resources, prompting more help desk tickets and decreased productivity for the entire organization.
Mitigating Active Directory lockouts is made simple with Messageware Exchange Protocol Guard (EPG). Our advanced Exchange Server security protects organizations from logon and password attacks, in addition to providing extensive real-time reporting and alerts of suspicious connections. In this article, we’ll explore the top six common causes of Active Directory account lockouts and provide some practical solutions to fix them. Whether you’re an IT professional or a user experiencing account lockouts, this article will provide valuable insights to help you solve this frustrating issue.
Common Causes of Active Directory Account Lockouts
Account lockouts can occur for various reasons, and identifying the root cause is crucial in resolving the issue. Here are six common causes of Active Directory account lockouts:
- Hackers and Password Guessing Attacks
A hacking attempt on an Active Directory account can lead to lockout. If the attacker repeatedly tries to guess the password, it will trigger the account lockout policy. Common techniques are brute-force attacks (systematically trying numerous password combinations), or dictionary attacks (using a list of commonly used passwords). These repeated failed login attempts can trigger the account lockout threshold and temporarily or permanently lock the targeted account.
To mitigate password guessing attacks enforce strong password policies that require users to create complex passwords and change them frequently.
- Outdated Windows Cached Credentials
Another common cause of Active Directory account lockouts is outdated windows cached credentials. When a user logs in to their account, their credentials are stored in the local cache. If the user changes their password, the cached credentials may become outdated, and any attempt to use them will result in an account lockout. This can also occur if the user logs in to their account from a different device, and the cached credentials on the original device become outdated.
To prevent account lockouts caused by outdated cached credentials, you can clear the cached credentials (click here for Windows 11) on the user’s device. This can be done by opening the Credential Manager on the user’s device and deleting any stored credentials. Alternatively, you can disable the local cache on the user’s device, forcing them to enter their credentials each time they log in.
- Mobile Devices and Disconnected Sessions
Mobile devices and disconnected sessions can also cause account lockouts. When a user logs in on a mobile device, the device may store the user’s credentials. This can result in an account lockout when the user attempts to use those credentials on another device. Disconnected sessions can also cause account lockouts if the user logs in to their account from one device and then logs in again from another device before logging out from the first device.
To prevent account lockouts caused by mobile devices and disconnected sessions, you can configure your Active Directory policies to limit the number of concurrent logins for each user account. This will prevent users from logging in to their account from multiple devices simultaneously. Additionally, you can enforce logoff policies that automatically log out users who have been inactive for a specified period.
- Services Using Expired Passwords
Many organizations use services that require user accounts to have passwords that expire after a certain period. However, if the user does not update their password before it expires, any services using that password will cause an account lockout. This can happen if the user has a service running on their device that is using an expired password.
To prevent Active Directory account lockouts caused by services using expired passwords, you can configure your Active Directory policies to send notifications to users when their password is about to expire. Additionally, you can enforce password policies that require users to change their passwords before they expire.
- Workstations and Shared Accounts
Workstations and shared accounts can also cause account lockouts. When a user logs in to their account on a shared workstation, any attempt to use their credentials on another device can result in an account lockout. Similarly, shared accounts can cause account lockouts if multiple users attempt to log in to the account simultaneously.
To prevent account lockouts caused by workstations and shared accounts, you can configure your Active Directory policies to limit the number of devices that can use a single account. Additionally, you can enforce strict password policies for shared accounts and require users to log in to their accounts from dedicated workstations.
- Users Forgetting Their Passwords
When a user forgets their password in an Active Directory environment, it can lead to them being locked out of their account. Active Directory has an account lockout policy that specifies the maximum number of failed login attempts before an account gets locked. When a user repeatedly enters the wrong password, exceeding the defined threshold, the account can be temporarily or permanently locked, depending on the configuration.
If a user forgets their password and attempts to reset it, they may encounter security measures such as security questions or multifactor authentication (MFA). If they are unable to provide the correct answers or complete the additional authentication steps, the password reset process may fail, resulting in a locked account.
How to Troubleshoot Account Lockout Issues
Identifying the root cause of account lockouts is essential in resolving the issue. Here are the steps to troubleshoot account lockout issues:
- Check the event logs on the domain controller to identify the source of the lockout.
- Identify the user account that is causing the lockout.
- Check the user’s device to see if any cached credentials are causing the lockout.
- Check for any active sessions that may be causing the lockout.
- Check for any services that may be using an expired password.
- Check for any mobile devices that may be using the user’s credentials.
- Use the Active Directory Users and Computers tool to reset the user’s password.
- Clear any cached credentials on the user’s device.
Best Practices for Preventing Account Lockouts
Preventing account lockouts requires a proactive approach to security. Here are some best practices for preventing account lockouts:
- Enforce strong password policies that require users to create complex passwords and change them frequently.
- Limit the number of concurrent logins for each user account.
- Enforce logoff policies that automatically log out users who have been inactive for a specified period.
- Configure your Active Directory policies to send notifications to users when their password is about to expire.
- Limit the number of devices that can use a single account.
- Enforce strict password policies for shared accounts.
- Require users to log in to their accounts from dedicated workstations.
- Educate users on the importance of security and the risks of malware and password guessing attacks.
- Implementing additional security measures and active directory management tools.
Tools for Managing Active Directory
- Active Directory Users and Computers: This tool is included with Windows Server and allows you to manage user accounts, groups, and computers.
- Active Directory Administrative Center: This tool provides a graphical user interface for managing Active Directory and includes many advanced features.
- PowerShell: PowerShell is a powerful command-line tool that allows you to automate many tasks in Active Directory.
- Messageware Exchange Protocol Guard (EPG): EPG software provides logon intelligence and security controls for the most widely used Exchange Server services.
Preventing Active Directory account lockouts with a third-party solution
With a third-party solution you can easily add protection to all Exchange Server protocols. Messageware Exchange Protocol Guard (EPG) protects on-premise Exchange Servers by providing advanced login intelligence and control for Microsoft Exchange Servers by monitoring for attacks that often cause AD account lockouts. Start your free trial now.
Account lockouts can be a frustrating issue for both IT professionals and users. However, by identifying the root cause of the lockout and implementing best practices for preventing it, you can ensure that your organization’s resources remain secure and accessible. Use the tools and techniques outlined in this article to troubleshoot account lockout issues and manage your Active Directory with confidence.