Title

MongoDB must check the validity of all data inputs except those specifically identified by the organization. (Cat II impact)

Discussion

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.

Check Content

As a client program assembles a query in MongoDB, it builds a BSON object, not a string. Thus traditional SQL injection attacks are not a problem. However, MongoDB operations permit arbitrary JavaScript expressions to be run directly on the server. If the "security.javascriptEnabled" option is set to "true" in the config file, this is a finding. Starting with MongoDB 3.2, database-level document validation can be configured for specific collections. Configured validation rules for the selected database can be viewed via the db.getSisterDB("database_name").getCollectionInfos() command in mongo shell. If validation is desired, but no rules are set, the valdiationAction is not "error" or the "bypassDocumentValidation" option is used for write commands on the application side, this is a finding.

Fix Text

Disable the javascriptEnabled option in the config file. security: javascriptEnabled: false If document validation is needed, it should be configured according to the documentation page at https://docs.mongodb.com/manual/core/document-validation/.

Additional Identifiers

Rule ID: SV-221181r879652_rule

Vulnerability ID: V-221181

Group Title: SRG-APP-000251-DB-000160

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.