CVE-2024-2338 in PostgreSQL Anonymizer
Summary
by MITRE • 03/08/2024
PostgreSQL Anonymizer v1.2 contains a SQL injection vulnerability that allows a user who owns a table to elevate to superuser when dynamic masking is enabled. PostgreSQL Anonymizer enables users to set security labels on tables to mask specified columns. There is a flaw that allows complex expressions to be provided as a value. This expression is then later used as it to create the masked views leading to SQL Injection. If dynamic masking is enabled, this will lead to privilege escalation to superuser after the label is created. Users that don't own a table, especially masked users cannot exploit this vulnerability. The problem is resolved in v1.3.
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Analysis
by VulDB Data Team • 02/13/2025
The PostgreSQL Anonymizer vulnerability identified as CVE-2024-2338 represents a critical security flaw that exploits the dynamic masking functionality within the anonymization framework. This vulnerability specifically targets the way the tool processes security labels and complex expressions when creating masked views, creating a pathway for privilege escalation that directly impacts database security posture. The flaw exists within the core implementation of how user-defined expressions are handled during the masking process, where insufficient input validation allows maliciously crafted expressions to be executed within the database context.
The technical exploitation of this vulnerability occurs through the dynamic masking feature that enables users to apply security labels to database tables for column masking operations. When a user with table ownership creates a security label containing a complex expression, the anonymizer processes this expression without adequate sanitization or validation. This processing step transforms the user-provided expression into a view creation statement that ultimately executes within the database context, creating a classic SQL injection vector. The vulnerability is particularly dangerous because it leverages legitimate database functionality to achieve unauthorized privilege escalation rather than exploiting traditional injection points.
The operational impact of this vulnerability extends beyond simple data exposure to encompass full administrative control of the database system. When dynamic masking is enabled and a malicious user with table ownership creates a specially crafted security label, the system grants them superuser privileges through the SQL injection mechanism. This privilege escalation allows attackers to bypass all database security controls, potentially leading to complete system compromise. The vulnerability specifically requires table ownership to exploit, which means that regular users without table ownership cannot leverage this issue, but it still represents a significant risk for organizations where users have elevated privileges or where privilege escalation is possible through other vectors.
Organizations using PostgreSQL Anonymizer v1.2 must immediately implement mitigations while planning for the mandatory upgrade to version 1.3, which contains the necessary patches to resolve this vulnerability. The recommended approach involves disabling dynamic masking functionality until the upgrade is complete, implementing strict access controls to limit table ownership privileges, and monitoring for suspicious security label creation activities. This vulnerability aligns with CWE-89 which classifies SQL injection flaws and demonstrates the importance of input validation in database security systems. The attack pattern follows ATT&CK technique T1078.004 which covers legitimate credentials usage, as the exploitation leverages existing table ownership rights to achieve unauthorized access. The vulnerability also highlights the broader category of privilege escalation attacks that can occur through improper handling of user-supplied data in database contexts, emphasizing the need for comprehensive security testing of database extensions and plugins that interact with user input.