Azure AD password policy - Key to success

Passwords are the first line of defense against unauthorized access in Microsoft Azure AD (Entra ID), making it crucial for organizations to implement robust password policies. A well-crafted Azure AD password policy helps strike a balance between security and usability, ensuring that users follow best practices for password complexity, length, and age. This article explores the default Azure AD password policy, customization options, common password hacking tactics, and best practices such as self-service password reset, multi-factor authentication (MFA), and passwordless authentication. By understanding these concepts and implementing the right measures, organizations can significantly enhance their security posture and protect their user accounts from various password-based attacks.

Understanding Password Hacking Tactics

To effectively protect user accounts, it is essential to understand the various tactics employed by hackers to compromise passwords. Microsoft, with its experience in safeguarding millions of user accounts, has gained valuable insights into these tactics. Password-only authentication is vulnerable to several types of attacks, including breach, phishing, malware, social engineering, and hammering.

Breach attacks, which account for 90% of password hacking attempts, involve stealing sensitive data, including usernames and hashed password information. Phishing attacks, representing 9% of attempts, lure users into divulging sensitive information through websites masquerading as trustworthy entities. Malware, such as keystroke loggers, can spy on users and steal their credentials. Social engineering tactics, while less common, involve hackers pretending to be support agents to trick users into revealing sensitive information.

Hammering attacks, although less frequent, involve hackers using common password lists to attempt access to a list of user accounts. Spear phishing, a more targeted form of phishing, involves crafting messages to lure users into downloading malicious software or visiting malicious links. Lastly, proof compromise attacks target a user's alternative email or phone, potentially compromising their MFA.

Creating Strong Passwords

To mitigate the risk of password hacking, Microsoft AD (Entra) recommends avoiding certain anti-patterns and adopting successful patterns. Anti-patterns include requiring long passwords, which can lead to poor password management behavior, and mandating multiple character sets, which may result in predictable password patterns. Password expiry policies can also drive users to adopt predictable patterns, such as incrementing numbers.

Successful patterns for creating strong passwords include banning common passwords to reduce susceptibility to brute-force attacks and educating users not to reuse passwords across different accounts. Enforcing multi-factor authentication (MFA) provides a strong defense against password-based attacks, while risk-based MFA maintains a balance between security and user experience. By following these guidelines, organizations can significantly improve the strength of their user passwords and reduce the risk of compromise.

Default Azure AD Password Policy

Microsoft cloud-only accounts are subject to a predefined password policy that aligns with industry best practices. Administrators cannot modify this policy, except for the password expiry duration and whether passwords expire at all. The default Azure AD password policy applies to all user accounts in Microsoft Entra ID and can be extended to user accounts synchronized from an on-premise AD DS environment using Microsoft Entra Connect.

The default policy allows for a wide range of characters, including uppercase and lowercase letters, numbers, and symbols. However, Unicode characters are not permitted. Passwords must be between 8 and 256 characters long and must include three out of four character types: lowercase, uppercase, numbers, and symbols.

By default, the password expiry duration is set to 90 days, but tenants created after 2021 have no default expiration value. The "Let passwords never expire" setting is set to false by default, indicating that passwords have an expiration date. When users change or reset their passwords, they cannot reuse their last password.

Enhancing Security Beyond the Default Policy

While the default Azure AD password policy provides a solid foundation, organizations can further enhance security by focusing on user education, implementing MFA, and exploring passwordless authentication options. Educating users to use unique passwords across their online accounts, especially for organizational accounts, is crucial in preventing password reuse attacks.

Implementing MFA adds an extra layer of security, requiring users to provide a second form of authentication in addition to their password. This significantly reduces the risk of unauthorized access, even if a password is compromised. Moreover, passwordless authentication, such as using the Microsoft Authenticator application, eliminates the need for passwords altogether, providing a more secure and user-friendly experience.

By leveraging the default Azure AD password policy and supplementing it with user education, MFA, and passwordless authentication, organizations can create a robust security framework that protects their user accounts from various password-related threats. Regularly reviewing and updating these policies in line with evolving security best practices ensures that the organization stays ahead of potential threats and maintains a strong security posture.

Self-Service Password Reset

Self-service password reset (SSPR) is a crucial feature that empowers users to change or reset their passwords without relying on administrators or help desk staff. By enabling SSPR, organizations can significantly reduce the burden on support teams and minimize user downtime caused by forgotten or expired passwords.

Microsoft Entra ID offers different SSPR scenarios based on the user's account type and the licensed plan. Cloud-only users can change their passwords with any Microsoft Entra ID plan, while resetting a forgotten password requires a Microsoft 365 Business Standard, Business Premium, or Microsoft Entra ID P1 or P2 license. For users synchronized from an on-premises directory, changing or resetting passwords is only available with Microsoft 365 Business Premium or Microsoft Entra ID P1 or P2 licenses.

Eliminating Weak Passwords

Weak passwords are a common target for bad actors, as they often include predictable patterns, widely used combinations, or common phrases. To protect against password spray attacks, which use a few commonly used passwords against many accounts, organizations must take proactive measures to block weak passwords and create custom banned password lists.

Microsoft Azure AD (Entra ID) Password Protection detects and blocks known weak passwords, and organizations can enhance this protection by customizing their banned password list. It is recommended to include terms specific to the organization, such as brand names, product names, locations, and company-specific internal terms and abbreviations.

Administrators can add up to 1,000 terms to the custom banned password list through the Microsoft Entra admin center. The list is case-insensitive, and Microsoft's password validation algorithm automatically blocks weak variants and combinations based on the provided base terms. In hybrid environments, the security benefits of Microsoft Entra Password Protection can be extended to the on-premises AD DS environment.

Conclusion

Implementing a robust Azure AD password policy is essential for safeguarding user accounts and protecting organizations from password-based attacks. By understanding the various tactics employed by hackers and adopting best practices for creating strong passwords, organizations can significantly reduce the risk of unauthorized access.