Title

The EDB Postgres Advanced Server must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. (Cat II impact)

Discussion

Preventing nonprivileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. System documentation should include a definition of the functionality considered privileged. Depending on circumstances, privileged functions can include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Nonprivileged users are individuals that do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from nonprivileged users. A privileged function in the DBMS/database 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 There may also be Data Manipulation Language (DML) statements that, subject to context, should be regarded as privileged. Possible examples include: TRUNCATE TABLE; DELETE, or DELETE affecting more than n rows, for some n, or DELETE without a WHERE clause; UPDATE or UPDATE affecting more than n rows, for some n, or UPDATE without a WHERE clause; any SELECT, INSERT, UPDATE, or DELETE to an application-defined security table executed by other than a security principal. Depending on the capabilities of the DBMS and the design of the database and associated applications, the prevention of unauthorized use of privileged functions may be achieved by means of DBMS security features, database triggers, other mechanisms, or a combination of these.

Check Content

Review the system documentation to obtain the definition of the database/DBMS functionality considered privileged in the context of the system in question. To determine nonprivileged user access to database objects use the following SQL command: "SELECT grantee, privilege_type, table_name FROM information_schema.role_table_grants WHERE grantee='<username>';" If any functionality considered privileged has access privileges granted to nonprivileged users, this is a finding.

Fix Text

Revoke any privileges to privileged functionality by executing the REVOKE command as documented here: http://www.postgresql.org/docs/current/static/sql-revoke.html

Additional Identifiers

Rule ID: SV-259273r938872_rule

Vulnerability ID: V-259273

Group Title: SRG-APP-000340-DB-000304

Expert Comments

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