Ivanti Sentry 9.x NDM Security Technical Implementation Guide

Multi-factor authentication (MFA) is when two or more factors are used to confirm the identity of an individual who is requesting access to digital information resources. Valid factors include something the individual knows (e.g., username and password), something the individual has (e.g., a smartcard or token), or something the individual is (e.g., a fingerprint or biometric). Legacy information system environments only use a single factor for authentication, typically a username and password combination. Although two pieces of data are used in a username and password combination, this is still considered single factor because an attacker can obtain access simply by learning what the user knows. Common attacks against single-factor authentication are attacks on user passwords. These attacks include brute force password guessing, password spraying, and password credential stuffing. MFA, along with strong user account hygiene, helps mitigate against the threat of having account passwords discovered by an attacker. Even in the event of a password compromise, with MFA implemented and required for interactive login, the attacker still needs to acquire something the user has or replicate a piece of user’s biometric digital presence. Private industry recognizes and uses a wide variety of MFA solutions. However, DOD public key infrastructure (PKI) is the only prescribed method approved for DOD organizations to implement MFA. For authentication purposes, centralized DOD certificate authorities (CA) issue PKI certificate key pairs (public and private) to individuals using the prescribed x.509 format. The private certificates that have been generated by the issuing CA are downloaded and saved to smartcards which, within DOD, are referred to as common access cards (CAC) or personal identity verification (PIV) cards. This happens at designated DOD badge facilities. The CA maintains a record of the corresponding public keys for use with PKI-enabled environments. Privileged user smartcards, or "alternate tokens", function in the same manner, so this requirement applies to all interactive user sessions (authorized and privileged users). Note: This requirement is used in conjunction with the use of a centralized authentication server (e.g., AAA, RADIUS, LDAP), a separate but equally important requirement. The MFA configuration of this requirement provides identification and the first phase of authentication (the challenge and validated response, thereby confirming the PKI certificate that was presented by the user). The centralized authentication server will provide the second phase of authentication (the digital presence of the PKI ID as a valid user in the requested security domain) and authorization. The centralized authentication server will map validated PKI identities to valid user accounts and determine access levels for authenticated users based on security group membership and role. In cases where the centralized authentication server is not utilized by the network device for user authorization, the network device must map the authenticated identity to the user account for PKI-based authentication.

Without mapping the PKI certificate to a unique user account, the ability to determine the identities of individuals or the status of their non-repudiation is considerably impacted during forensic analysis. A strength of using PKI as MFA is that it can help ensure only the assigned individual is using their associated user account. This can only be accomplished if the network device is configured to enforce the relationship which binds PKI certificates to unique user accounts. Local accounts (accounts created, stored, and maintained locally on the network device) should be avoided in lieu of using a centrally managed directory service. Local accounts empower the same workgroup who will be operating the network infrastructure to also control and manipulate access methods, thus creating operational autonomy. This undesirable approach breaks the concept of separation of duties. Additionally, local accounts are susceptible to poor cyber hygiene because they create another user database that must be maintained by the operator, whose primary focus is on running the network. Such examples of poor hygiene include dormant accounts that are not disabled or deleted, employees who have left the organization but whose accounts are still present, periodic password and hash rotation, password complexity shortcomings, increased exposure to insider threat, etc. For reasons such as this, local users on network devices are frequently the targets of cyber-attacks. Instead, organizations should explore examples of centrally managed account services. These examples include the implementation of AAA concepts like the use of external RADIUS and LDAP directory service brokers.

Unapproved mechanisms that are used for authentication to the cryptographic module are not validated and therefore cannot be relied upon to provide confidentiality or integrity, and DOD data may be compromised. Sentry utilizing encryption is required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets DOD requirements. However, authentication algorithms must configure security processes to use only FIPS-approved and NIST-recommended authentication algorithms.

Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level, or de-allocating networking assignments at the application level if multiple application sessions are using a single, operating system-level network connection. This does not mean that the device terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session.

This requires the use of secure protocols instead of their unsecured counterparts, such as SSH instead of telnet, SCP instead of FTP, and HTTPS instead of HTTP. If unsecured protocols (lacking cryptographic mechanisms) are used for sessions, the contents of those sessions will be susceptible to eavesdropping, potentially putting sensitive data (including administrator passwords) at risk of compromise and potentially allowing hijacking of maintenance sessions.

Without syslog enabled it will be difficult for an ISSO to correlate the users behavior and identify potential threats within the logs.

Network devices running an unsupported operating system lack current security fixes required to mitigate the risks associated with recent vulnerabilities.