Splunk Enterprise 8.x for Linux Security Technical Implementation Guide

Once an attacker establishes access to an application, the attacker often attempts to create a persistent method of re-establishing access. One way to accomplish this is for the attacker to simply create a new account. Sending notification of account creation events to the system administrator and ISSO is one method for mitigating this risk. To address access requirements, many application developers choose to integrate their applications with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. Such integration allows the application developer to off-load those access control functions and focus on core application features and functionality. Satisfies: SRG-APP-000291-AU-000200, SRG-APP-000292-AU-000420, SRG-APP-000294-AU-000430, SRG-APP-000294-AU-000440

Display of the DOD-approved use notification before granting access to the application ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with DTM-08-060. Use the following verbiage for applications that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't."

If the application is not configured to collate records based on the time when the events occurred, the ability to perform forensic analysis and investigations across multiple components is significantly degraded. Centralized log aggregation must also include logs from databases and servers (e.g., Windows) that do not natively send logs using the syslog protocol.

If authorized individuals do not have the ability to modify auditing parameters in response to a changing threat environment, the organization may not be able to respond effectively and important forensic information may be lost. The organization must define and document log retention requirements for each device and host and then configure Splunk Enterprise to comply with the required retention period. This requirement enables organizations to extend or limit auditing as necessary to meet organizational requirements. Auditing that is limited to conserve information system resources may be extended to address certain threat situations.

Without restricting which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

If security personnel are not notified immediately upon storage volume utilization reaching 75 percent, they are unable to plan for storage capacity expansion. Although this may be part of the operating system function, for the enterprise events management system, this is most often a function managed through the application since it is a critical function and requires the use of a large amount of external storage.

It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without a real-time alert, security personnel may be unaware of an impending failure of the audit function and application operation may be adversely affected.

If the system were to continue processing after audit failure, actions could be taken on the system that could not be tracked and recorded for later forensic analysis. To perform this function, some type of heartbeat configuration with all of the devices and hosts must be configured.

Protection of log data includes ensuring log data is not accidentally lost or deleted. Backing up log records to a different system or onto separate media than the system being audited on an organizationally defined frequency helps to ensure that in the event of a catastrophic system failure, the log records will be retained. This helps to ensure that a compromise of the information system being audited does not also result in a compromise of the log records. This requirement only applies to applications that have a native backup capability for log records. Operating system backup requirements cover applications that do not provide native backup functions.

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determine how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. In most enterprise environments, this requirement is usually mitigated by a properly configured external authentication system, like LDAP. Splunk local authentication takes precedence over other forms of authentication, and cannot be disabled. The mitigation settings in this requirement apply in the event a local account is created.

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determine how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. In most enterprise environments, this requirement is usually mitigated by a properly configured external authentication system, like LDAP. Splunk local authentication takes precedence over other forms of authentication, and cannot be disabled. The mitigation settings in this requirement apply in the event a local account is created.

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determine how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. In most enterprise environments, this requirement is usually mitigated by a properly configured external authentication system, like LDAP. Splunk local authentication takes precedence over other forms of authentication, and cannot be disabled. The mitigation settings in this requirement apply in the event a local account is created.

The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password. In most enterprise environments, this requirement is usually mitigated by a properly configured external authentication system, like LDAP. Splunk local authentication takes precedence over other forms of authentication, and cannot be disabled. The mitigation settings in this requirement apply in the event a local account is created.

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor in determining how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Special characters are those characters that are not alphanumeric. Examples include: ~ ! @ # $ % ^ *. In most enterprise environments, this requirement is usually mitigated by a properly configured external authentication system, like LDAP. Splunk local authentication takes precedence over other forms of authentication, and cannot be disabled. The mitigation settings in this requirement apply in the event a local account is created.

Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed at specific intervals. If the application does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the system and/or application passwords could be compromised. This requirement does not include emergency administration accounts that are meant for access to the application in case of failure. These accounts are not required to have maximum password lifetime restrictions. In most enterprise environments, this requirement is usually mitigated by a properly configured external authentication system, like LDAP. Splunk local authentication takes precedence over other forms of authentication, and cannot be disabled. The mitigation settings in this requirement apply in the event a local account is created.

Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. To meet password policy requirements, passwords need to be changed at specific policy-based intervals. If the information system or application allows the user to consecutively reuse their password when that password has exceeded its defined lifetime, the end result is a password that is not changed as per policy requirements. In most enterprise environments, this requirement is usually mitigated by a properly configured external authentication system, like LDAP. Splunk local authentication takes precedence over other forms of authentication, and cannot be disabled. The mitigation settings in this requirement apply in the event a local account is created.