Title

The ALG providing user authentication intermediary services must implement replay-resistant authentication mechanisms for network access to nonprivileged accounts. (Cat II impact)

Discussion

A replay attack may enable an unauthorized user to gain access to the application. Authentication sessions between the authenticator and the application validating the user credentials must not be vulnerable to a replay attack. An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message. A nonprivileged account is any account with the authorizations of a nonprivileged user. Privileged roles are organization-defined roles assigned to individuals that allow those individuals to perform certain security-relevant functions that ordinary users are not authorized to perform. Security relevant roles include key management, account management, network and system administration, database administration, and web administration. Techniques used to address this include protocols using nonces (e.g., numbers generated for a specific one time use) or challenges (e.g., TLS). Additional techniques include time-synchronous or challenge-response one-time authenticators. This requirement applies to ALGs that provide user authentication intermediary services.

Check Content

If the ALG does not provide user authentication intermediary services, this is not applicable. Verify the ALG is configured to implement replay-resistant authentication mechanisms for network access to nonprivileged accounts. If the ALG does not implement replay-resistant authentication mechanisms for network access to nonprivileged accounts, this is a finding.

Fix Text

If user authentication intermediary services are provided, configure the ALG to implement replay-resistant authentication mechanisms for network access to nonprivileged accounts.

Additional Identifiers

Rule ID: SV-204949r981631_rule

Vulnerability ID: V-204949

Group Title: SRG-NET-000147

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.