Database Security Requirements Guide

Database management includes the ability to control the number of users and user sessions utilizing a DBMS. Unlimited concurrent connections to the DBMS could allow a successful Denial of Service (DoS) attack by exhausting connection resources; and a system can also fail or be degraded by an overload of legitimate users. Limiting the number of concurrent sessions per user is helpful in reducing these risks.

This requirement addresses concurrent session control for a single account. It does not address concurrent sessions by a single user via multiple system accounts; and it does not deal with the total number of sessions across all accounts.

The capability to limit the number of concurrent sessions per user must be configured in or added to the DBMS (for example, by use of a logon trigger), when this is technically feasible. Note that it is not sufficient to limit sessions via a web server or application server alone, because legitimate users and adversaries can potentially connect to the DBMS by other means.

The organization will need to define the maximum number of concurrent sessions by account type, by account, or a combination thereof. In deciding on the appropriate number, it is important to consider the work requirements of the various types of users. For example, 2 might be an acceptable limit for general users accessing the database via an application; but 10 might be too few for a database administrator using a database management GUI tool, where each query tab and navigation pane may count as a separate session.

(Sessions may also be referred to as connections or logons, which for the purposes of this requirement are synonyms.)

Authentication with a DoD-approved PKI certificate does not necessarily imply authorization to access the DBMS. 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 the DBMS 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.

Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

Audit records can be generated from various components within the DBMS (e.g., process, module). Certain specific application functionalities may be audited as well. The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records.

DoD has defined the list of events for which the DBMS will provide an audit record generation capability as the following:

(i) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels);

(ii) Access actions, such as successful and unsuccessful logon attempts, privileged activities, or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; and

(iii) All account creation, modification, disabling, and termination actions.

Organizations may define additional events requiring continuous or ad hoc auditing.

Under some circumstances, it may be useful to monitor who/what is reading privilege/permission/role information. Therefore, it must be possible to configure auditing to do this. DBMSs typically make such information available through views or functions.

This requirement addresses explicit requests for privilege/permission/role membership information. It does not refer to the implicit retrieval of privileges/permissions/role memberships that the DBMS continually performs to determine if any and every action on the database is permitted.

Session auditing is for use when a user's activities are under investigation. To be sure of capturing all activity during those periods when session auditing is in use, it needs to be in operation for the whole time the DBMS is running.

Information system auditing capability is critical for accurate forensic analysis. Without establishing when events occurred, it is impossible to establish, correlate, and investigate the events relating to an incident.

In order to compile an accurate risk assessment and provide forensic analysis, it is essential for security personnel to know the date and time when events occurred.

Associating the date and time with detected events in the application and audit logs provides a means of investigating an attack; recognizing resource utilization or capacity thresholds; or identifying an improperly configured application.

Database software is capable of a range of actions on data stored within the database. It is important, for accurate forensic analysis, to know exactly when specific actions were performed. This requires the date and time an audit record is referring to. If date and time information is not recorded and stored with the audit record, the record itself is of very limited use.

Information system auditing capability is critical for accurate forensic analysis. Without establishing the source of the event, it is impossible to establish, correlate, and investigate the events relating to an incident.

In order to compile an accurate risk assessment and provide forensic analysis, it is essential for security personnel to know where events occurred, such as application components, modules, session identifiers, filenames, host names, and functionality.

In addition to logging where events occur within the application, the application must also produce audit records that identify the application itself as the source of the event.

Associating information about the source of the event within the application provides a means of investigating an attack; recognizing resource utilization or capacity thresholds; or identifying an improperly configured application.

Information system auditing capability is critical for accurate forensic analysis. Without information that establishes the identity of the subjects (i.e., users or processes acting on behalf of users) associated with the events, security personnel cannot determine responsibility for the potentially harmful event.

Identifiers (if authenticated or otherwise known) include, but are not limited to, user database tables, primary key values, user names, or process identifiers.

Internal system clocks are typically a feature of server hardware and are maintained and used by the operating system. They are typically synchronized with an authoritative time server at regular intervals.

Without an internal system clock used as the reference for the time stored on each event to provide a trusted common reference for the time, forensic analysis would be impeded. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events.

Time stamps generated by the internal system clock and used by the DBMS shall include both date and time. The time may be expressed in Coordinated Universal Time (UTC), a modern continuation of Greenwich Mean Time (GMT), or local time with an offset from UTC.

If time sources other than the system time are used for audit records, the timeline of events can get skewed. This makes forensic analysis of the logs much less reliable.

If audit data were to become compromised, then competent forensic analysis and discovery of the true source of potentially malicious system activity is impossible to achieve.

To ensure the veracity of audit data the information system and/or the application must protect audit information from unauthorized modification.

This requirement can be achieved through multiple methods that will depend upon system architecture and design. Some commonly employed methods include ensuring log files enjoy the proper file system permissions and limiting log data locations.

Applications providing a user interface to audit data will leverage user permissions and roles identifying the user accessing the data and the corresponding rights that the user enjoys in order to make access decisions regarding the modification of audit data.

Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity.

Modification of database audit data could mask the theft of, or the unauthorized modification of, sensitive data stored in the database.

Protecting audit data also includes identifying and protecting the tools used to view and manipulate log data.

Depending upon the log format and application, system and application log tools may provide the only means to manipulate and manage application and system log data. It is, therefore, imperative that access to audit tools be controlled and protected from unauthorized access.

Applications providing tools to interface with audit data will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys in order make access decisions regarding the access to audit tools.

Audit tools include, but are not limited to, OS-provided audit tools, vendor-provided audit tools, and open source audit tools needed to successfully view and manipulate audit information system activity and records.

If an attacker were to gain access to audit tools, he could analyze audit logs for system weaknesses or weaknesses in the auditing itself. An attacker could also manipulate logs to hide evidence of malicious activity.

Protecting audit data also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit data.

Applications providing tools to interface with audit data will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys in order make access decisions regarding the deletion of audit tools.

Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators.

When dealing with change control issues, it should be noted any changes to the hardware, software, and/or firmware components of the information system and/or application can have significant effects on the overall security of the system.

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 access to information system components for purposes of initiating changes, including upgrades and modifications.

DBA and other privileged administrative or application owner accounts are granted privileges that allow actions that can have a great impact on database security and operation. It is especially important to grant privileged access to only those persons who are qualified and authorized to use them.

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 rely on unauthorized owner accounts, these objects may be lost when an account is removed.

Information systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions).

It is detrimental for software products to provide, or install by default, functionality exceeding requirements or mission objectives. Examples include, but are not limited to, installing advertising software, demonstrations, or browser plugins not related to requirements or providing a wide array of functionality, not required for every mission, that cannot be disabled.

DBMSs must adhere to the principles of least functionality by providing only essential capabilities.

Demonstration and sample database objects and applications present publicly known attack points for malicious users. These demonstration and sample objects are meant to provide simple examples of coding specific functions and are not developed to prevent vulnerabilities from being introduced to the DBMS and host system.

Information systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions).

It is detrimental for software products to provide, or install by default, functionality exceeding requirements or mission objectives.

DBMSs must adhere to the principles of least functionality by providing only essential capabilities.

Unused, unnecessary DBMS components increase the attack vector for the DBMS by introducing additional targets for attack. By minimizing the services and applications installed on the system, the number of potential vulnerabilities is reduced. Components of the system that are unused and cannot be uninstalled must be disabled. The techniques available for disabling components will vary by DBMS product, OS, and the nature of the component and may include DBMS configuration settings, OS service settings, OS file access security, and DBMS user/role permissions.

In order to prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols/services on information systems.

Applications are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., email and web services); however, doing so increases risk over limiting the services provided by any one component.

To support the requirements and principles of least functionality, the application must support the organizational requirements providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business or to address authorized quality of life issues.

Database Management Systems using ports, protocols, and services deemed unsafe are open to attack through those ports, protocols, and services. This can allow unauthorized access to the database and through the database to other components of the information system.

OS/enterprise authentication and identification must be used (SRG-APP-000023-DB-000001). Native DBMS authentication may be used only when circumstances make it unavoidable; and must be documented and AO-approved.

The DOD standard for authentication is DOD-approved PKI certificates. Authentication based on user ID and password may be used only when it is not possible to employ a PKI certificate, and requires AO approval.

In such cases, the DOD standards for password complexity and lifetime must be implemented. DBMS products that can inherit the rules for these from the operating system or access control program (e.g., Microsoft Active Directory) must be configured to do so. For other DBMSs, the rules must be enforced using available configuration parameters or custom code.

The DoD standard for authentication is DoD-approved PKI certificates.

Authentication based on User ID and Password may be used only when it is not possible to employ a PKI certificate, and requires AO approval.

In such cases, passwords need to be protected at all times, and encryption is the standard method for protecting passwords during transmission.

DBMS passwords sent in clear text format across the network are vulnerable to discovery by unauthorized users. Disclosure of passwords may easily lead to unauthorized access to the database.

The DoD standard for authentication is DoD-approved PKI certificates. PKI certificate-based authentication is performed by requiring the certificate holder to cryptographically prove possession of the corresponding private key.

If the private key is stolen, an attacker can use the private key(s) to impersonate the certificate holder. In cases where the DBMS-stored private keys are used to authenticate the DBMS to the system’s clients, loss of the corresponding private keys would allow an attacker to successfully perform undetected man in the middle attacks against the DBMS system and its clients.

Both the holder of a digital certificate and the issuing authority must take careful measures to protect the corresponding private key. Private keys should always be generated and protected in FIPS 140-2 or 140-3 validated cryptographic modules.

All access to the private key(s) of the DBMS must be restricted to authorized and authenticated users. If unauthorized users have access to one or more of the DBMS's private keys, an attacker could gain access to the key(s) and use them to impersonate the database on the network or otherwise perform unauthorized actions.

The DoD standard for authentication is DoD-approved PKI certificates.

Normally, with PKI authentication, the interaction with the user for authentication will be handled by a software component separate from the DBMS, such as ActivIdentity ActivClient. However, in cases where the DBMS controls the interaction, this requirement applies.

To prevent the compromise of authentication information such as passwords and PINs during the authentication process, the feedback from the system must not provide any information that would allow an unauthorized user to compromise the authentication mechanism.

Obfuscation of user-provided authentication secrets when typed into the system is a method used in addressing this risk.

Displaying asterisks when a user types in a password or a smart card PIN is an example of obscuring feedback of authentication secrets.

This calls for review of applications, 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.

Non-organizational users include all information system users other than organizational users, which include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors, guest researchers, individuals from allied nations).

Non-organizational users shall be uniquely identified and authenticated for all accesses other than those accesses explicitly identified and documented by the organization when related to the use of anonymous access, such as accessing a web server.

Accordingly, a risk assessment is used in determining the authentication needs of the organization.

Scalability, practicality, and security are simultaneously considered in balancing the need to ensure ease of use for access to federal information and information systems with the need to protect and adequately mitigate risk to organizational operations, organizational assets, individuals, other organizations, and the Nation.

Captured sessions can be reused in "replay" attacks. This requirement limits the ability of adversaries to capture and continue to employ previously valid session IDs.

This requirement focuses on communications protection for the DBMS session rather than for the network packet. The intent of this control is to establish grounds for confidence at each end of a communications session in the ongoing identity of the other party and in the validity of the information being transmitted.

Session IDs are tokens generated by DBMSs to uniquely identify a user's (or process's) session. DBMSs will make access decisions and execute logic based on the session ID.

Unique session IDs help to reduce predictability of said identifiers. Unique session IDs address man-in-the-middle attacks, including session hijacking or insertion of false information into a session. If the attacker is unable to identify or guess the session information related to pending application traffic, they will have more difficulty in hijacking the session or otherwise manipulating valid sessions.

When a user logs out, or when any other session termination event occurs, the DBMS must terminate the user session(s) to minimize the potential for sessions to be hijacked.

One class of man-in-the-middle, or session hijacking, attack involves the adversary guessing at valid session identifiers based on patterns in identifiers already known.

The preferred technique for thwarting guesses at Session IDs is the generation of unique session identifiers using a FIPS 140-2 or 140-3 approved random number generator.

However, it is recognized that available DBMS products do not all implement the preferred technique yet may have other protections against session hijacking. Therefore, other techniques are acceptable, provided they are demonstrated to be effective.

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.

Preserving information system state information helps to facilitate system restart and return to the operational mode of the organization with less disruption of mission/business processes.

Since it is usually not possible to test this capability in a production environment, systems should either be validated in a testing environment or prior to installation. This requirement is usually a function of the design of the IDPS component. Compliance can be verified by acceptance/validation processes or vendor attestation.

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.

The purpose of this control is to prevent information, including encrypted representations of information, produced by the actions of a prior user/role (or the actions of a process acting on behalf of a prior user/role) from being available to any current user/role (or current process) that obtains access to a shared system resource (e.g., registers, main memory, secondary storage) after the resource has been released back to the information system. Control of information in shared resources is also referred to as object reuse.

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.

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. In such cases, the attacker deduces the manner in which SQL statements are being processed, either from inside knowledge or by observing system behavior in response to invalid inputs. When the attacker identifies scenarios where SQL queries are being assembled by application code (which may be within the database or separate from it) and executed dynamically, the attacker is then able to craft input strings that subvert the intent of the query. Potentially, the attacker can gain unauthorized access to data, including security settings, and severely corrupt or destroy the database.

The principal protection against code injection is not to use dynamic execution except where it provides necessary functionality that cannot be utilized otherwise. Use strongly typed data items rather than general-purpose strings as input parameters to task-specific, pre-compiled stored procedures and functions (and triggers).

When dynamic execution is necessary, ways to mitigate the risk include the following, which should be implemented both in the on-screen application and at the database level, in the stored procedures:
-- Allow strings as input only when necessary.
-- Rely on data typing to validate numbers, dates, etc. Do not accept invalid values. If substituting other values for them, think carefully about whether this could be subverted.
-- Limit the size of input strings to what is truly necessary.
-- If single quotes/apostrophes, double quotes, semicolons, equals signs, angle brackets, or square brackets will never be valid as input, reject them.
-- If comment markers will never be valid as input, reject them. In SQL, these are -- or /* */
-- If HTML and XML tags, entities, comments, etc., will never be valid, reject them.
-- If wildcards are present, reject them unless truly necessary. In SQL these are the underscore and the percentage sign, and the word ESCAPE is also a clue that wildcards are in use.
-- If SQL key words, such as SELECT, INSERT, UPDATE, DELETE, CREATE, ALTER, DROP, ESCAPE, UNION, GRANT, REVOKE, DENY, MODIFY will never be valid, reject them. Use case-insensitive comparisons when searching for these. Bear in mind that some of these words, particularly Grant (as a person's name), could also be valid input.
-- If there are range limits on the values that may be entered, enforce those limits.
-- Institute procedures for inspection of programs for correct use of dynamic coding, by a party other than the developer.
-- Conduct rigorous testing of program modules that use dynamic coding, searching for ways to subvert the intended use.
-- Record the inspection and testing in the system documentation.
-- Bear in mind that all this applies not only to screen input, but also to the values in an incoming message to a web service or to a stored procedure called by a software component that has not itself been hardened in these ways. Not only can the caller be subject to such vulnerabilities; it may itself be the attacker.

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.

If the DBMS provides too much information in error logs and administrative messages to the screen, this could lead to compromise. The structure and content of error messages need to be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.

Some default DBMS error messages can contain information that could aid an attacker in, among others things, identifying the database type, host address, or state of the database. Custom errors may contain sensitive customer information.

It is important that detailed error messages be visible only to those who are authorized to view them; that general users receive only generalized acknowledgment that errors have occurred; and that these generalized messages appear only when relevant to the user's task. For example, a message along the lines of, "An error has occurred. Unable to save your changes. If this problem persists, please contact your help desk" would be relevant. A message such as "Warning: your transaction generated a large number of page splits" would likely not be relevant.

Administrative users authorized to review detailed error messages typically are the ISSO, ISSM, SA, and DBA. Other individuals or roles may be specified according to organization-specific needs, with appropriate approval.

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.

If a user cannot explicitly end a DBMS session, the session may remain open and be exploited by an attacker; this is referred to as a zombie session.

Such logout may be explicit or implicit. Examples of explicit are: clicking on a "Log Out" link or button in the application window; clicking the Windows Start button and selecting "Log Out" or "Shut Down." Examples of implicit logout are: closing the application's (main) window; powering off the workstation without invoking the OS shutdown.

Both the explicit and implicit logouts must be detected by the DBMS.

In all cases, the DBMS must ensure that the user's DBMS session and all processes owned by the session are terminated.

This should not, however, interfere with batch processes/jobs initiated by the user during his/her online session: these should be permitted to run to completion.

Without the association of security labels to information, there is no basis for the DBMS 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 the DBMS product, a third-party product, or custom application code.

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.

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.

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.

Organizations are required to use a central log management system, so, under normal conditions, the audit space allocated to the DBMS on its own server will not be an issue. However, space will still be required on the DBMS server for audit records in transit, and, under abnormal conditions, this could fill up. Since a requirement exists to halt processing upon audit failure, a service outage would result.

If support personnel are not notified immediately upon storage volume utilization reaching 75%, they are unable to plan for storage capacity expansion.

The appropriate support staff include, at a minimum, the ISSO and the DBA/SA.

If time stamps are not consistently applied and there is no common time reference, it is difficult to perform forensic analysis.

Time stamps generated by the DBMS must include date and time. Time is commonly expressed in Coordinated Universal Time (UTC), a modern continuation of Greenwich Mean Time (GMT), or local time with an offset from UTC.

Some DBMS products offer a data type called TIMESTAMP that is not a representation of date and time. Rather, it is a database state counter and does not correspond to calendar and clock time. This requirement does not refer to that meaning of TIMESTAMP.

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.

The DBMS 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.

Without auditing the enforcement of access restrictions against changes to configuration, it would be difficult to identify attempted attacks and an audit trail would not be available for forensic investigation for after-the-fact actions.

Enforcement actions are the methods or mechanisms used to prevent unauthorized changes to configuration settings. Enforcement action methods may be as simple as denying access to a file based on the application of file permissions (access restriction). Audit items may consist of lists of actions blocked by access restrictions or changes identified after the fact.

The DOD standard for authentication of an interactive user is the presentation of a Common Access Card (CAC) or other physical token bearing a valid, current, DOD-issued Public Key Infrastructure (PKI) certificate, coupled with a Personal Identification Number (PIN) to be entered by the user at the beginning of each session and whenever reauthentication is required.

Without reauthentication, users may access resources or perform tasks for which they do not have authorization.

When applications provide the capability to change security roles or escalate the functional capability of the application, it is critical the user reauthenticate.

In addition to the reauthentication requirements associated with session locks, organizations may require reauthentication of individuals and/or devices in other situations, including (but not limited to) the following circumstances:

(i) When authenticators change;
(ii) When roles change;
(iii) When security categories of information systems change;
(iv) When the execution of privileged functions occurs;
(v) After a fixed period of time; or
(vi) Periodically.

Within the DOD, the minimum circumstances requiring reauthentication are privilege escalation and role changes.

Only DoD-approved external PKIs have been evaluated to ensure that they have security controls and identity vetting procedures in place which are sufficient for DoD systems to rely on the identity asserted in the certificate. PKIs lacking sufficient security controls and identity vetting procedures risk being compromised and issuing certificates that enable adversaries to impersonate legitimate users.

The authoritative list of DoD-approved PKIs is published at http://iase.disa.mil/pki-pke/interoperability.

This requirement focuses on communications protection for the DBMS session rather than for the network packet.

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 the DBMS 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.

Information can be either unintentionally or maliciously disclosed or modified during preparation for transmission, including, for example, during aggregation, at protocol transformation points, and during packing/unpacking. These unauthorized disclosures or modifications compromise the confidentiality or integrity of the information.

Use of this requirement will be limited to situations where the data owner has a strict requirement for ensuring data integrity and confidentiality is maintained at every step of the data transfer and handling process.

When transmitting data, the DBMS, associated applications, and infrastructure must leverage transmission protection mechanisms.

A common vulnerability is unplanned behavior when invalid inputs are received. This requirement guards against adverse or unintended system behavior caused by invalid inputs, where information system responses to the invalid input may be disruptive or cause the system to fail into an unsafe state.

The behavior will be derived from the organizational and system requirements and includes, but is not limited to, notification of the appropriate personnel, creating an audit record, and rejecting invalid input.

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.

Security flaws with software applications, including database management systems, are discovered daily. Vendors are constantly updating and patching their products to address newly discovered security vulnerabilities. Organizations (including any contractor to the organization) are required to promptly install security-relevant software updates (e.g., patches, service packs, and hot fixes). Flaws discovered during security assessments, continuous monitoring, incident response activities, or information system error handling must also be addressed expeditiously.

Organization-defined time periods for updating security-relevant software may vary based on a variety of factors including, for example, the security category of the information system or the criticality of the update (i.e., severity of the vulnerability related to the discovered flaw).

This requirement will apply to software patch management solutions that are used to install patches across the enclave and also to applications themselves that are not part of that patch management solution. For example, many browsers today provide the capability to install their own patch software. Patch criticality, as well as system criticality, will vary. Therefore, the tactical situations regarding the patch management process will also vary. This means that the time period utilized must be a configurable parameter. Time frames for application of security-relevant software updates may be dependent upon the Information Assurance Vulnerability Management (IAVM) process.

The application will be configured to check for and install security-relevant software updates within an identified time period from the availability of the update. The specific time period will be defined by an authoritative source (e.g., IAVM, CTOs, DTMs, and STIGs).

Changes to the security configuration must be tracked.

This requirement applies to situations where security data is retrieved or modified via data manipulation operations, as opposed to via specialized security functionality.

In an SQL environment, types of access include, but are not necessarily limited to:
SELECT
INSERT
UPDATE
DELETE
EXECUTE

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

Changes in categories of information must be tracked. Without an audit trail, unauthorized access to protected data could go undetected.

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

For detailed information on categorizing information, refer to FIPS Publication 199, Standards for Security Categorization of Federal Information and Information Systems, and FIPS Publication 200, Minimum Security Requirements for Federal Information and Information Systems.

Failed attempts to change the permissions, privileges, and roles granted to users and roles must be tracked. Without an audit trail, unauthorized attempts to elevate or restrict privileges could go undetected.

In an SQL environment, adding permissions is typically done via the GRANT command, or, in the negative, the DENY command.

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

Failed attempts to change the permissions, privileges, and roles granted to users and roles must be tracked. Without an audit trail, unauthorized attempts to elevate or restrict privileges could go undetected.

In an SQL environment, modifying permissions is typically done via the GRANT, REVOKE, and DENY commands.

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

Changes in the database objects (tables, views, procedures, functions) that record and control permissions, privileges, and roles granted to users and roles must be tracked. Without an audit trail, unauthorized changes to the security subsystem could go undetected. The database could be severely compromised or rendered inoperative.

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

Changes in categories of information must be tracked. Without an audit trail, unauthorized access to protected data could go undetected.

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

For detailed information on categorizing information, refer to FIPS Publication 199, Standards for Security Categorization of Federal Information and Information Systems, and FIPS Publication 200, Minimum Security Requirements for Federal Information and Information Systems.

Failed attempts to change the permissions, privileges, and roles granted to users and roles must be tracked. Without an audit trail, unauthorized attempts to elevate or restrict privileges could go undetected.

In an SQL environment, deleting permissions is typically done via the REVOKE or DENY command.

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

The removal of security objects from the database/DBMS would seriously degrade a system's information assurance posture. If such an action is attempted, it must be logged.

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

Changes in categories of information must be tracked. Without an audit trail, unauthorized access to protected data could go undetected.

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

For detailed information on categorizing information, refer to FIPS Publication 199, Standards for Security Categorization of Federal Information and Information Systems, and FIPS Publication 200, Minimum Security Requirements for Federal Information and Information Systems.

For completeness of forensic analysis, it is necessary to track failed attempts to log on to the DBMS. While positive identification may not be possible in a case of failed authentication, as much information as possible about the incident must be captured.

Without tracking privileged activity, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

System documentation should include a definition of the functionality considered privileged.

A privileged function in this context is any operation that modifies the structure of the database, its built-in logic, or its security settings. This would include all Data Definition Language (DDL) statements and all security-related statements. In an SQL environment, it encompasses, but is not necessarily limited to:
CREATE
ALTER
DROP
GRANT
REVOKE
DENY

Note that it is particularly important to audit, and tightly control, any action that weakens the implementation of this requirement itself, since the objective is to have a complete audit trail of all administrative activity.

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

For completeness of forensic analysis, it is necessary to track who logs on to the DBMS.

Concurrent connections by the same user from multiple workstations may be valid use of the system; or such connections may be due to improper circumvention of the requirement to use the CAC for authentication; or they may indicate unauthorized account sharing; or they may be because an account has been compromised.

(If the fact of multiple, concurrent logons by a given user can be reliably reconstructed from the log entries for other events (logons/connections; voluntary and involuntary disconnections), then it is not mandatory to create additional log entries specifically for this.)

Without tracking all or selected types of access to all or selected objects (tables, views, procedures, functions, etc.), it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

In an SQL environment, types of access include, but are not necessarily limited to:
SELECT
INSERT
UPDATE
DELETE
EXECUTE

To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

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.

For detailed information, refer to NIST FIPS Publication 140-3, Security Requirements For Cryptographic Modules. Note that the product's cryptographic modules must be validated and certified by NIST as FIPS-compliant.

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.

For detailed information, refer to NIST FIPS Publication 140-3, Security Requirements For Cryptographic Modules. Note that the product's cryptographic modules must be validated and certified by NIST as FIPS-compliant.

Configuring the DBMS to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements.

In addition to this SRG, sources of guidance on security and information assurance exist. These include NSA configuration guides, CTOs, DTMs, and IAVMs. The DBMS must be configured in compliance with guidance from all such relevant sources.

Disabling expired, inactive, or otherwise anomalous accounts supports the concepts of least privilege and least functionality, which reduce the attack surface of the system.

Automated mechanisms for centralized reviews and analyses include Security Information and Event Management products.

Software and firmware components prevented from installation unless signed with recognized and approved certificates include software and firmware version updates, patches, service packs, device drivers, and basic input/output system updates. Organizations can identify applicable software and firmware components by type, by specific items, or a combination of both. Digital signatures and organizational verification of such signatures is a method of code authentication.

The purpose of requiring a device that is separate from the system to which the user is attempting to gain access for one of the factors during multifactor authentication is to reduce the likelihood of compromising authenticators or credentials stored on the system. Adversaries may be able to compromise such authenticators or credentials and subsequently impersonate authorized users. Implementing one of the factors on a separate device (e.g., a hardware token), provides a greater strength of mechanism and an increased level of assurance in the authentication process.

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.

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.

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.

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.

Nonlocal maintenance and diagnostic activities are conducted by individuals who communicate through either an external or internal network. Communications paths can be logically separated using encryption.

A Trusted Platform Module (TPM) is an example of a hardware-protected data store that can be used to protect cryptographic keys.

Synchronization of internal system clocks with an authoritative source provides uniformity of time stamps for systems with multiple system clocks and systems connected over a network.