Title

Microsoft Entra ID must, for password-based authentication, verify when users create or update passwords that the passwords are not found on the list of commonly used, expected, or compromised passwords. (Cat II impact)

Discussion

Password-based authentication applies to passwords regardless of whether they are used in single-factor or multifactor authentication. Long passwords or passphrases are preferable over shorter passwords. Enforced composition rules provide marginal security benefits while decreasing usability. However, organizations may choose to establish certain rules for password generation (e.g., minimum character length for long passwords) under certain circumstances and can enforce this requirement in IA-5(1)(h). Account recovery can occur, for example, in situations when a password is forgotten. Cryptographically protected passwords include salted one-way cryptographic hashes of passwords. The list of commonly used, compromised, or expected passwords includes passwords obtained from previous breach corpuses, dictionary words, and repetitive or sequential characters. The list includes context-specific words, such as the name of the service, username, and derivatives thereof.

Check Content

As an authorized administrator, browse to https://portal.azure.us/#view/Microsoft_AAD_ConditionalAccess/PasswordProtectionBlade. Check the "Custom banned passwords" section. If "Enforce custom list" has not be configured to "Yes" and a custom banned password list has not been populated, this is a finding.

Fix Text

As an authorized administrator, browse to https://portal.azure.us/#view/Microsoft_AAD_ConditionalAccess/PasswordProtectionBlade. Enable the Custom banned password list by selecting "Yes" next to the "Enforce custom list" option. Populate the "Custom banned password list". The list must be one word per line, with a maximum of 1000 words. The words are case insensitive, and common character substitutions (o for 0, etc) are automatically considered.

Additional Identifiers

Rule ID: SV-270475r1085680_rule

Vulnerability ID: V-270475

Group Title: SRG-APP-000845

Expert Comments

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