MongoDB Enterprise Advanced 3.x Security Technical Implementation Guide

MongoDB must provide audit record generation capability for DoD-defined auditable events within all DBMS/database components. Satisfies: SRG-APP-000089-DB-000064, SRG-APP-000080-DB-000063, SRG-APP-000090-DB-000065, SRG-APP-000091-DB-000066, SRG-APP-000091-DB-000325, SRG-APP-000092-DB-000208, SRG-APP-000093-DB-000052, SRG-APP-000095-DB-000039, SRG-APP-000096-DB-000040, SRG-APP-000097-DB-000041, SRG-APP-000098-DB-000042, SRG-APP-000099-DB-000043, SRG-APP-000100-DB-000201, SRG-APP-000101-DB-000044, SRG-APP-000109-DB-000049, SRG-APP-000356-DB-000315, SRG-APP-000360-DB-000320, SRG-APP-000381-DB-000361, SRG-APP-000492-DB-000332, SRG-APP-000492-DB-000333, SRG-APP-000494-DB-000344, SRG-APP-000494-DB-000345, SRG-APP-000495-DB-000326, SRG-APP-000495-DB-000327, SRG-APP-000495-DB-000328, SRG-APP-000495-DB-000329, SRG-APP-000496-DB-000334, SRG-APP-000496-DB-000335, SRG-APP-000498-DB-000346, SRG-APP-000498-DB-000347, SRG-APP-000499-DB-000330, SRG-APP-000499-DB-000331, SRG-APP-000501-DB-000336, SRG-APP-000501-DB-000337, SRG-APP-000502-DB-000348, SRG-APP-000502-DB-000349, SRG-APP-000503-DB-000350, SRG-APP-000503-DB-000351, SRG-APP-000504-DB-000354, SRG-APP-000504-DB-000355, SRG-APP-000505-DB-000352, SRG-APP-000506-DB-000353, SRG-APP-000507-DB-000356, SRG-APP-000507-DB-000357, SRG-APP-000508-DB-000358, SRG-APP-000515-DB-000318

If audit data were to become compromised, then competent forensic analysis and discovery of the true source of potentially malicious system activity is difficult, if not impossible, to achieve. In addition, access to audit records provides information an attacker could potentially use to his or her advantage. To ensure the veracity of audit data, the information system and/or the application must protect audit information from any and all unauthorized access. This includes read, write, copy, etc. This requirement can be achieved through multiple methods which will depend upon system architecture and design. Some commonly employed methods include ensuring log files enjoy the proper file system permissions utilizing file system protections and limiting log data location. Additionally, applications with user interfaces to audit records should not allow for the unfettered manipulation of or access to those records via the application. If the application provides access to the audit data, the application becomes accountable for ensuring that audit information is protected from unauthorized access. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Satisfies: SRG-APP-000118-DB-000059, SRG-APP-000119-DB-000060, SRG-APP-000120-DB-000061

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. Satisfies: SRG-APP-000121-DB-000202, SRG-APP-000122-DB-000203, SRG-APP-000122-DB-000204

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 potentially have significant effects on the overall security of the system. Multiple applications can provide a cumulative negative effect. A vulnerability and subsequent exploit to one application can lead to an exploit of other applications sharing the same security context. For example, an exploit to a web server process that leads to unauthorized administrative access to host system directories can most likely lead to a compromise of all applications hosted by the same system. Database software not installed using dedicated directories both threatens and is threatened by other hosted applications. Access controls defined for one application may by default provide access to the other application's database objects or directories. Any method that provides any level of separation of security context assists in the protection between applications.

If MongoDB 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 must 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.

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.

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 MongoDB 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. Satisfies: SRG-APP-000141-DB-000092, SRG-APP-000142-DB-000094

To assure accountability and prevent unauthenticated access, organizational users must be identified and authenticated to prevent potential misuse and compromise of the system. Organizational users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Organizational users (and any processes acting on behalf of users) must be uniquely identified and authenticated for all accesses, except the following: (i) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and (ii) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals using shared accounts, for detailed accountability of individual activity.

The DoD standard for authentication is DoD-approved PKI certificates. Once a PKI certificate has been validated, it must be mapped to a DBMS user account for the authenticated identity to be meaningful to MongoDB and useful for authorization decisions.

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 must 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. Satisfies: SRG-APP-000180-DB-000115, SRG-APP-000211-DB-000122, SRG-APP-000211-DB-000124

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 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. Failure to a known safe state helps prevent systems from failing to a state that may cause loss of data or unauthorized access to system resources. Systems that fail suddenly and with no incorporated failure state planning may leave the hosting system available but with a reduced security protection capability. Preserving information system state data also facilitates system restart and return to the operational mode of the organization with less disruption of mission/business processes. Databases must fail to a known consistent state. Transactions must be successfully completed or rolled back. In general, security mechanisms should be designed so that a failure will follow the same execution path as disallowing the operation. For example, application security methods, such as isAuthorized(), isAuthenticated(), and validate(), should all return false if there is an exception during processing. If security controls can throw exceptions, they must be very clear about exactly what that condition means. Abort refers to stopping a program or function before it has finished naturally. The term abort refers to both requested and unexpected terminations. Satisfies: SRG-APP-000225-DB-000153, SRG-APP-000226-DB-000147

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.

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. Satisfies: SRG-APP-000243-DB-000373, SRG-APP-000243-DB-000374

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). 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. Satisfies: SRG-APP-000251-DB-000391, SRG-APP-000251-DB-000392

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. 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 MongoDB 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, 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.

Without the association of security labels to information, there is no basis for MongoDB 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 MongoDB product, a third-party product, or custom application code. Satisfies: SRG-APP-000311-DB-000308, SRG-APP-000313-DB-000309, SRG-APP-000313-DB-000310

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. Satisfies: SRG-APP-000328-DB-000301, SRG-APP-000340-DB-000304

Without the ability to centrally manage the content captured in the audit records, identification, troubleshooting, and correlation of suspicious behavior would be difficult and could lead to a delayed or incomplete analysis of an ongoing attack. The content captured in audit records must be managed from a central location (necessitating automation). Centralized management of audit records and logs provides for efficiency in maintenance and management of records, as well as the backup and archiving of those records. MongoDB may write audit records to database tables, to files in the file system, to other kinds of local repository, or directly to a centralized log management system. Whatever the method used, it must be compatible with off-loading the records to the centralized system.

In order to ensure sufficient storage capacity for the audit logs, MongoDB must be able to allocate audit record storage capacity. Although another requirement (SRG-APP-000515-DB-000318) mandates that audit data be off-loaded to a centralized log management system, it remains necessary to provide space on the database server to serve as a buffer against outages and capacity limits of the off-loading mechanism. The task of allocating audit record storage capacity is usually performed during initial installation of MongoDB and is closely associated with the DBA and system administrator roles. The DBA or system administrator will usually coordinate the allocation of physical drive space with the application owner/installer and the application will prompt the installer to provide the capacity information, the physical location of the disk, or both. In determining the capacity requirements, consider such factors as: total number of users; expected number of concurrent users during busy periods; number and type of events being monitored; types and amounts of data being captured; the frequency/speed with which audit records are off-loaded to the central log management system; and any limitations that exist on MongoDB's ability to reuse the space formerly occupied by off-loaded records.

Organizations are required to use a central log management system, so, under normal conditions, the audit space allocated to MongoDB on its own server will not be an issue. However, space will still be required on MongoDB 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.

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. MongoDB 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.

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.

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.

If cached authentication information is out-of-date, the validity of the authentication information may be questionable.

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 MongoDB 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 MongoDB 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. Satisfies: SRG-APP-000428-DB-000386, SRG-APP-000429-DB-000387

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, MongoDB, associated applications, and infrastructure must leverage transmission protection mechanisms.

Information can be either unintentionally or maliciously disclosed or modified during reception, 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. This requirement applies only to those applications that are either distributed or can allow access to data nonlocally. 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 receiving data, MongoDB, associated applications, and infrastructure must leverage 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.

Configuring MongoDB 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. MongoDB must be configured in compliance with guidance from all such relevant sources.