CVE-2016-2192 in PostgreSQL PL-Java
Summary
by MITRE
PostgreSQL PL/Java before 1.5.0 allows remote authenticated users to alter type mappings for types they do not own.
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Analysis
by VulDB Data Team • 10/14/2019
PostgreSQL PL/Java represents a critical vulnerability in the database system's Java integration layer that affects versions prior to 1.5.0. This flaw resides within the type mapping mechanism that allows Java functions to interact with PostgreSQL data types, creating a privilege escalation path for authenticated attackers who can manipulate type mappings for objects they do not own. The vulnerability stems from insufficient access control checks within the PL/Java extension's type registration and modification processes, where the system fails to properly validate ownership permissions before allowing type mapping alterations.
The technical implementation of this vulnerability involves the manipulation of PostgreSQL's internal type system through the PL/Java extension interface. When authenticated users execute specific operations against type mappings, the system does not verify whether the requesting user has sufficient privileges to modify the target type definitions. This oversight creates a scenario where malicious actors with minimal database access can alter type mappings that belong to other users or system objects, potentially leading to data corruption, unauthorized data access, or privilege escalation within the database environment. The flaw operates at the intersection of database access control and Java integration, making it particularly dangerous in multi-tenant database environments where different users share the same PostgreSQL instance.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to manipulate how data flows between PostgreSQL and Java applications. An attacker could potentially modify type mappings to cause data type conversion errors, leading to data loss or application crashes, or more insidiously, create mappings that allow unauthorized access to sensitive data through Java function calls. This vulnerability directly impacts the integrity and confidentiality of database operations, particularly in environments where PL/Java is used for complex data processing or integration with external Java applications. The implications are especially severe in enterprise environments where database security is paramount and where multiple applications rely on PL/Java for data type handling.
Organizations should immediately upgrade to PL/Java version 1.5.0 or later to remediate this vulnerability, as no effective workarounds exist for the underlying access control flaw. System administrators should conduct comprehensive audits of existing PL/Java installations to identify any vulnerable versions and implement strict access controls for database users with PL/Java privileges. The vulnerability aligns with CWE-284 Access Control Issues and can be mapped to ATT&CK technique T1078 Valid Accounts, as it leverages legitimate authenticated database access to perform unauthorized operations. Security monitoring should include detection of unusual type mapping modifications and user activities that might indicate exploitation attempts, while network segmentation and principle of least privilege should be enforced to minimize potential damage from successful exploitation.