MS SQL Server 2016 Database Security Technical Implementation Guide

U_MS_SQL_Server_2016_Database_STIG_V1R3_Manual-xccdf.xml

This Security Technical Implementation Guide is published as a tool to improve the security of Department of Defense (DoD) information systems. The requirements are derived from the National Institute of Standards and Technology (NIST) 800-53 and related documents. Comments or proposed revisions to this document should be sent via email to the following address: [email protected]
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Version / Release: V1R3

Published: 2018-09-18

Updated At: 2018-11-03 13:47:22

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Vuln Rule Version CCI Severity Title Description
SV-93767r1_rule SQL6-D0-000100 CCI-000015 MEDIUM SQL Server databases must integrate with an organization-level authentication/access mechanism providing account management and automation for all users, groups, roles, and any other principals. Enterprise environments make account management for applications and databases challenging and complex. A manual process for account management functions adds the risk of a potential oversight or other error. Managing accounts for the same person in multiple places is inefficient and prone to problems with consistency and synchronization. A comprehensive application account management process that includes automation helps to ensure that accounts designated as requiring attention are consistently and promptly addressed. Examples include, but are not limited to, using automation to take action on multiple accounts designated as inactive, suspended, or terminated, or by disabling accounts located in non-centralized account stores, such as multiple servers. Account management functions can also include: assignment of group or role membership; identifying account type; specifying user access authorizations (i.e., privileges); account removal, update, or termination; and administrative alerts. The use of automated mechanisms can include, for example: using email or text messaging to notify account managers when users are terminated or transferred; using the information system to monitor account usage; and using automated telephone notification to report atypical system account usage. SQL Server must be configured to automatically utilize organization-level account management functions, and these functions must immediately enforce the organization's current account policy. Automation may be comprised of differing technologies that when placed together contain an overall mechanism supporting an organization's automated account management requirements.
SV-93771r1_rule SQL6-D0-000300 CCI-000213 HIGH SQL Server must enforce approved authorizations for logical access to information and system resources in accordance with applicable access control policies. Authentication with a DoD-approved PKI certificate does not necessarily imply authorization to access SQL Server. To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DoD-approved PKIs, all DoD systems, including databases, must be properly configured to implement access control policies. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Access control policies include identity-based policies, role-based policies, and attribute-based policies. Access enforcement mechanisms include access control lists, access control matrices, and cryptography. These policies and mechanisms must be employed by the application to control access between users (or processes acting on behalf of users) and objects (e.g., devices, files, records, processes, programs, and domains) in the information system. This requirement is applicable to access control enforcement applications, a category that includes database management systems. If SQL Server does not follow applicable policy when approving access, it may be in conflict with networks or other applications in the information system. This may result in users either gaining or being denied access inappropriately and in conflict with applicable policy.
SV-93773r2_rule SQL6-D0-000400 CCI-000166 HIGH SQL Server must protect against a user falsely repudiating by ensuring only clearly unique Active Directory user accounts can connect to the database. Non-repudiation of actions taken is required in order to maintain data integrity. Examples of particular actions taken by individuals include creating information, sending a message, approving information (e.g., indicating concurrence or signing a contract), and receiving a message. Non-repudiation protects against later claims by a user of not having created, modified, or deleted a particular data item or collection of data in the database. In designing a database, the organization must define the types of data and the user actions that must be protected from repudiation. The implementation must then include building audit features into the application data tables and configuring the DBMS's audit tools to capture the necessary audit trail. Design and implementation also must ensure that applications pass individual user identification to the DBMS, even where the application connects to the DBMS with a standard, shared account. If the computer account of a remote computer is granted access to a SQL Server database, any service or scheduled task running as NT AUTHORITY\SYSTEM or NT AUTHORITY\NETWORK SERVICE can log into the instance and perform actions. These actions cannot be traced back to a specific user or process.
SV-93775r1_rule SQL6-D0-000500 CCI-000166 LOW SQL Server must protect against a user falsely repudiating by use of system-versioned tables (Temporal Tables). Non-repudiation of actions taken is required in order to maintain data integrity. Examples of particular actions taken by individuals include creating information, sending a message, approving information (e.g., indicating concurrence or signing a contract), and receiving a message. Non-repudiation protects against later claims by a user of not having created, modified, or deleted a particular data item or collection of data in the database. In designing a database, the organization must define the types of data and the user actions that must be protected from repudiation. The implementation must then include building audit features into the application data tables and configuring SQL Server's audit tools to capture the necessary audit trail. Design and implementation also must ensure that applications pass individual user identification to SQL Server, even where the application connects to SQL Server with a standard, shared account. Applications should use temporal tables to track the changes and history of sensitive data.
SV-93777r2_rule SQL6-D0-000600 CCI-000166 HIGH SQL Server must protect against a user falsely repudiating by ensuring databases are not in a trust relationship. Non-repudiation of actions taken is required in order to maintain data integrity. Examples of particular actions taken by individuals include creating information, sending a message, approving information (e.g., indicating concurrence or signing a contract), and receiving a message. Non-repudiation protects against later claims by a user of not having created, modified, or deleted a particular data item or collection of data in the database. SQL Server provides the ability for high privileged accounts to impersonate users in a database using the TRUSTWORTHY feature. This will allow members of the fixed database role to impersonate any user within the database. 
SV-93779r1_rule SQL6-D0-000700 CCI-000171 MEDIUM SQL Server must allow only the ISSM (or individuals or roles appointed by the ISSM) to select which auditable events are to be audited. Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent or interfere with the auditing of critical events. Suppression of auditing could permit an adversary to evade detection. Misconfigured audits can 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.
SV-93781r1_rule SQL6-D0-001100 CCI-001499 MEDIUM SQL Server must limit privileges to change software modules, to include stored procedures, functions, and triggers. If the system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. Accordingly, only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. Unmanaged changes that occur to the database software libraries or configuration can lead to unauthorized or compromised installations.
SV-93783r1_rule SQL6-D0-001200 CCI-001499 MEDIUM SQL Server must limit privileges to change software modules, to include stored procedures, functions, and triggers, and links to software external to SQL Server. If the system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. Accordingly, only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. Unmanaged changes that occur to the database software libraries or configuration can lead to unauthorized or compromised installations.
SV-93785r1_rule SQL6-D0-001300 CCI-001499 MEDIUM Database objects (including but not limited to tables, indexes, storage, stored procedures, functions, triggers, links to software external to SQL Server, etc.) must be owned by database/DBMS principals authorized for ownership. Within the database, object ownership implies full privileges to the owned object, including the privilege to assign access to the owned objects to other subjects. Database functions and procedures can be coded using definer's rights. This allows anyone who utilizes the object to perform the actions if they were the owner. If not properly managed, this can lead to privileged actions being taken by unauthorized individuals. Conversely, if critical tables or other objects in SQL Server rely on unauthorized owner accounts, these objects may be lost when an account is removed.
SV-93787r1_rule SQL6-D0-001400 CCI-001499 MEDIUM The role(s)/group(s) used to modify database structure (including but not necessarily limited to tables, indexes, storage, etc.) and logic modules (stored procedures, functions, triggers, links to software external to SQL Server, etc.) must be restricted to authorized users. If SQL Server were to allow any user to make changes to database structure or logic, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. Accordingly, only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. Unmanaged changes that occur to the database software libraries or configuration can lead to unauthorized or compromised installations.
SV-93789r1_rule SQL6-D0-001500 CCI-001665 MEDIUM In the event of a system failure, hardware loss or disk failure, SQL Server must be able to restore necessary databases with least disruption to mission processes. Failure to a known state can address safety or security in accordance with the mission/business needs of the organization. Failure to a known secure state helps prevent a loss of confidentiality, integrity, or availability in the event of a failure of the information system or a component of the system. In the event of a system failure, SQL Server must be able to bring the database back to a consistent state.
SV-93791r1_rule SQL6-D0-001600 CCI-001199 MEDIUM The Database Master Key encryption password must meet DOD password complexity requirements. Weak passwords may be easily guessed. When passwords are used to encrypt keys used for encryption of sensitive data, then the confidentiality of all data encrypted using that key is at risk.
SV-93793r1_rule SQL6-D0-001700 CCI-001199 MEDIUM The Database Master Key must be encrypted by the Service Master Key, where a Database Master Key is required and another encryption method has not been specified. When not encrypted by the Service Master Key, system administrators or application administrators may access and use the Database Master Key to view sensitive data that they are not authorized to view. Where alternate encryption means are not feasible, encryption by the Service Master Key may be necessary. To help protect sensitive data from unauthorized access by DBAs, mitigations may be in order. Mitigations may include automatic alerts or other audit events when the Database Master Key is accessed outside of the application or by a DBA account.
SV-93795r1_rule SQL6-D0-001800 CCI-001199 MEDIUM The Certificate used for encryption must be backed up, stored offline and off-site. Backup and recovery of the Certificate used for encryption is critical to the complete recovery of the database. Not having this key can lead to loss of data during recovery.
SV-93797r1_rule SQL6-D0-001900 CCI-001084 LOW SQL Server must isolate security functions from non-security functions. An isolation boundary provides access control and protects the integrity of the hardware, software, and firmware that perform security functions. Security functions are the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Developers and implementers can increase the assurance in security functions by employing well-defined security policy models; structured, disciplined, and rigorous hardware and software development techniques; and sound system/security engineering principles. Database Management Systems typically separate security functionality from non-security functionality via separate databases or schemas. Database objects or code implementing security functionality should not be commingled with objects or code implementing application logic. When security and non-security functionality are commingled, users who have access to non-security functionality may be able to access security functionality.
SV-93799r1_rule SQL6-D0-002000 CCI-001090 MEDIUM Database contents must be protected from unauthorized and unintended information transfer by enforcement of a data-transfer policy. Applications, including DBMSs, must prevent unauthorized and unintended information transfer via shared system resources. Data used for the development and testing of applications often involves copying data from production. It is important that specific procedures exist for this process, to include the conditions under which such transfer may take place, where the copies may reside, and the rules for ensuring sensitive data are not exposed. Copies of sensitive data must not be misplaced or left in a temporary location without the proper controls.
SV-93801r1_rule SQL6-D0-002100 CCI-001310 MEDIUM SQL Server must check the validity of all data inputs except those specifically identified by the organization. Invalid user input occurs when a user inserts data or characters into an application's data entry fields and the application is unprepared to process that data. This results in unanticipated application behavior, potentially leading to an application or information system compromise. Invalid user input is one of the primary methods employed when attempting to compromise an application. With respect to database management systems, one class of threat is known as SQL Injection, or more generally, code injection. It takes advantage of the dynamic execution capabilities of various programming languages, including dialects of SQL. Potentially, the attacker can gain unauthorized access to data, including security settings, and severely corrupt or destroy the database. Even when no such hijacking takes place, invalid input that gets recorded in the database, whether accidental or malicious, reduces the reliability and usability of the system. Available protections include data types, referential constraints, uniqueness constraints, range checking, and application-specific logic. Application-specific logic can be implemented within the database in stored procedures and triggers, where appropriate. This calls for inspection of application source code, which will require collaboration with the application developers. It is recognized that in many cases, the database administrator (DBA) is organizationally separate from the application developers, and may have limited, if any, access to source code. Nevertheless, protections of this type are so important to the secure operation of databases that they must not be ignored. At a minimum, the DBA must attempt to obtain assurances from the development organization that this issue has been addressed, and must document what has been discovered.
SV-93803r1_rule SQL6-D0-002400 CCI-001312 MEDIUM SQL Server must provide non-privileged users with error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries. Any DBMS or associated application providing too much information in error messages on the screen or printout risks compromising the data and security of the system. The structure and content of error messages need to be carefully considered by the organization and development team. Databases can inadvertently provide a wealth of information to an attacker through improperly handled error messages. In addition to sensitive business or personal information, database errors can provide host names, IP addresses, user names, and other system information not required for troubleshooting but very useful to someone targeting the system. Carefully consider the structure/content of error messages. The extent to which information systems are able to identify and handle error conditions is guided by organizational policy and operational requirements. Information that could be exploited by adversaries includes, for example, logon attempts with passwords entered by mistake as the username, mission/business information that can be derived from (if not stated explicitly by) information recorded, and personal information, such as account numbers, social security numbers, and credit card numbers.
SV-93805r1_rule SQL6-D0-002500 CCI-002262 MEDIUM SQL Server must associate organization-defined types of security labels having organization-defined security label values with information in storage. Without the association of security labels to information, there is no basis for SQL Server to make security-related access-control decisions. Security labels are abstractions representing the basic properties or characteristics of an entity (e.g., subjects and objects) with respect to safeguarding information. These labels are typically associated with internal data structures (e.g., tables, rows) within the database and are used to enable the implementation of access control and flow control policies; reflect special dissemination, handling, or distribution instructions; or support other aspects of the information security policy. One example includes marking data as classified or FOUO. These security labels may be assigned manually or during data processing, but, either way, it is imperative these assignments are maintained while the data is in storage. If the security labels are lost when the data is stored, there is the risk of a data compromise. The mechanism used to support security labeling may be a feature of SQL Server, a third-party product, or custom application code.
SV-93807r1_rule SQL6-D0-002600 CCI-002263 MEDIUM SQL Server must associate organization-defined types of security labels having organization-defined security label values with information in process. Without the association of security labels to information, there is no basis for SQL Server to make security-related access-control decisions. Security labels are abstractions representing the basic properties or characteristics of an entity (e.g., subjects and objects) with respect to safeguarding information. These labels are typically associated with internal data structures (e.g., tables, rows) within the database and are used to enable the implementation of access control and flow control policies; reflect special dissemination, handling, or distribution instructions; or support other aspects of the information security policy. One example includes marking data as classified or FOUO. These security labels may be assigned manually or during data processing, but, either way, it is imperative these assignments are maintained while the data is in storage. If the security labels are lost when the data is stored, there is the risk of a data compromise. The mechanism used to support security labeling may be a feature of SQL Server, a third-party product, or custom application code.
SV-93809r1_rule SQL6-D0-002700 CCI-002264 MEDIUM SQL Server must associate organization-defined types of security labels having organization-defined security label values with information in transmission. Without the association of security labels to information, there is no basis for SQL Server to make security-related access-control decisions. Security labels are abstractions representing the basic properties or characteristics of an entity (e.g., subjects and objects) with respect to safeguarding information. These labels are typically associated with internal data structures (e.g., tables, rows) within the database and are used to enable the implementation of access control and flow control policies; reflect special dissemination, handling, or distribution instructions; or support other aspects of the information security policy. One example includes marking data as classified or FOUO. These security labels may be assigned manually or during data processing, but, either way, it is imperative these assignments are maintained while the data is in storage. If the security labels are lost when the data is stored, there is the risk of a data compromise. The mechanism used to support security labeling may be a feature of SQL Server, a third-party product, or custom application code.
SV-93811r1_rule SQL6-D0-002800 CCI-002165 LOW SQL Server must enforce discretionary access control policies, as defined by the data owner, over defined subjects and objects. Discretionary Access Control (DAC) is based on the notion that individual users are "owners" of objects and therefore have discretion over who should be authorized to access the object and in which mode (e.g., read or write). Ownership is usually acquired as a consequence of creating the object or via specified ownership assignment. DAC allows the owner to determine who will have access to objects they control. An example of DAC includes user-controlled table permissions. When discretionary access control policies are implemented, subjects are not constrained with regard to what actions they can take with information for which they have already been granted access. Thus, subjects that have been granted access to information are not prevented from passing (i.e., the subjects have the discretion to pass) the information to other subjects or objects. A subject that is constrained in its operation by Mandatory Access Control policies is still able to operate under the less rigorous constraints of this requirement. Thus, while Mandatory Access Control imposes constraints preventing a subject from passing information to another subject operating at a different sensitivity level, this requirement permits the subject to pass the information to any subject at the same sensitivity level. The policy is bounded by the information system boundary. Once the information is passed outside of the control of the information system, additional means may be required to ensure the constraints remain in effect. While the older, more traditional definitions of discretionary access control require identity-based access control, that limitation is not required for this use of discretionary access control.
SV-93813r1_rule SQL6-D0-002900 CCI-002233 MEDIUM Execution of stored procedures and functions that utilize execute as must be restricted to necessary cases only. In certain situations, to provide required functionality, a DBMS needs to execute internal logic (stored procedures, functions, triggers, etc.) and/or external code modules with elevated privileges. However, if the privileges required for execution are at a higher level than the privileges assigned to organizational users invoking the functionality applications/programs, those users are indirectly provided with greater privileges than assigned by organizations. Privilege elevation must be utilized only where necessary and protected from misuse.
SV-93815r1_rule SQL6-D0-003000 CCI-001812 MEDIUM SQL Server must prohibit user installation of logic modules (stored procedures, functions, triggers, views, etc.) without explicit privileged status. Allowing regular users to install software, without explicit privileges, creates the risk that untested or potentially malicious software will be installed on the system. Explicit privileges (escalated or administrative privileges) provide the regular user with explicit capabilities and control that exceed the rights of a regular user. DBMS functionality and the nature and requirements of databases will vary; so while users are not permitted to install unapproved software, there may be instances where the organization allows the user to install approved software packages such as from an approved software repository. The requirements for production servers will be more restrictive than those used for development and research. SQL Server must enforce software installation by users based upon what types of software installations are permitted (e.g., updates and security patches to existing software) and what types of installations are prohibited (e.g., software whose pedigree with regard to being potentially malicious is unknown or suspect) by the organization). In the case of a database management system, this requirement covers stored procedures, functions, triggers, views, etc.
SV-93817r1_rule SQL6-D0-003100 CCI-001813 MEDIUM SQL Server must enforce access restrictions associated with changes to the configuration of the database(s). Failure to provide logical access restrictions associated with changes to configuration may have significant effects on the overall security of the system. When dealing with access restrictions pertaining to change control, it should be noted that any changes to the hardware, software, and/or firmware components of the information system can potentially have significant effects on the overall security of the system. Accordingly, only qualified and authorized individuals should be allowed to obtain access to system components for the purposes of initiating changes, including upgrades and modifications.
SV-93819r2_rule SQL6-D0-003200 CCI-002450 MEDIUM SQL Server must use NSA-approved cryptography to protect classified information in accordance with the data owners requirements. Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The application must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. It is the responsibility of the data owner to assess the cryptography requirements in light of applicable federal laws, Executive Orders, directives, policies, regulations, and standards. NSA-approved cryptography for classified networks is hardware based. This requirement addresses the compatibility of a DBMS with the encryption devices.
SV-93821r1_rule SQL6-D0-003300 CCI-002475 MEDIUM SQL Server must implement cryptographic mechanisms to prevent unauthorized modification of organization-defined information at rest (to include, at a minimum, PII and classified information) on organization-defined information system components. DBMSs handling data requiring "data at rest" protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. These cryptographic mechanisms may be native to SQL Server or implemented via additional software or operating system/file system settings, as appropriate to the situation. Selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields). The decision whether and what to encrypt rests with the data owner and is also influenced by the physical measures taken to secure the equipment and media on which the information resides.
SV-93823r1_rule SQL6-D0-003400 CCI-002476 MEDIUM SQL Server must implement cryptographic mechanisms preventing the unauthorized disclosure of organization-defined information at rest on organization-defined information system components. SQL Server’s handling data requiring "data at rest" protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. These cryptographic mechanisms may be native to SQL Server or implemented via additional software or operating system/file system settings, as appropriate to the situation. Selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields). The decision whether and what to encrypt rests with the data owner and is also influenced by the physical measures taken to secure the equipment and media on which the information resides.