CVE-2024-2339 in PostgreSQL Anonymizer
Summary
by MITRE • 03/08/2024
PostgreSQL Anonymizer v1.2 contains a vulnerability that allows a user who owns a table to elevate to superuser. A user can define a masking function for a column and place malicious code in that function. When a privileged user applies the masking rules using the static masking or the anonymous dump method, the malicious code is executed and can grant escalated privileges to the malicious user. PostgreSQL Anonymizer v1.2 does provide a protection against this risk with the restrict_to_trusted_schemas option, but that protection is incomplete. Users that don't own a table, especially masked users cannot exploit this vulnerability. The problem is resolved in v1.3.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/13/2025
The vulnerability identified as CVE-2024-2339 affects PostgreSQL Anonymizer version 1.2 and represents a critical privilege escalation flaw that exploits the masking function mechanism within the database anonymization tool. This vulnerability operates through a sophisticated code injection vector where table owners can craft malicious masking functions that execute arbitrary code when privileged users apply anonymization operations. The flaw stems from insufficient input validation and code execution controls within the anonymization framework, allowing malicious actors with table ownership privileges to manipulate the system's security boundaries through carefully crafted function definitions.
The technical implementation of this vulnerability leverages the static masking and anonymous dump methods that are core features of the PostgreSQL Anonymizer tool. When a privileged user executes these operations, the system processes the defined masking functions without adequate sandboxing or privilege separation mechanisms. This creates a scenario where malicious code embedded within column masking functions can be executed with the privileges of the user performing the anonymization operation. The vulnerability specifically targets the trust model within the anonymizer, where the system assumes that masking functions defined by table owners are benign, failing to validate or isolate potentially dangerous code execution paths.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially compromise entire database systems. An attacker with table ownership can elevate their privileges to superuser level, gaining unrestricted access to all database resources including sensitive data, system configuration, and other user accounts. This represents a severe security risk in multi-tenant environments or systems where table ownership is not strictly controlled. The vulnerability affects the principle of least privilege by allowing unauthorized privilege escalation through legitimate anonymization workflows, potentially enabling data exfiltration, system manipulation, or complete database compromise. Organizations using PostgreSQL Anonymizer v1.2 face significant exposure risk as this flaw can be exploited without requiring additional attack vectors beyond gaining table ownership.
The incomplete protection mechanism provided by the restrict_to_trusted_schemas option demonstrates a flawed security approach that fails to address the root cause of the vulnerability. This protection mechanism, while attempting to limit the scope of the attack, does not fully mitigate the risk as it can be bypassed or circumvented under certain conditions. The vulnerability classification aligns with CWE-78 and CWE-79 within the Common Weakness Enumeration framework, specifically addressing code injection vulnerabilities and insufficient input sanitization. From an ATT&CK perspective, this vulnerability maps to privilege escalation techniques and potentially to execution through database tools, representing a significant threat to database security. The remediation in version 1.3 includes comprehensive code validation, stricter privilege controls, and enhanced isolation mechanisms for masking function execution, addressing both the immediate code injection vector and the underlying architectural weaknesses that enabled the vulnerability. Organizations should prioritize upgrading to PostgreSQL Anonymizer v1.3 and implementing additional monitoring for suspicious masking function definitions to prevent exploitation of this critical vulnerability.