CVE-2023-23554 in pg_ivm
Summary
by MITRE • 03/07/2023
Uncontrolled search path element vulnerability exists in pg_ivm versions prior to 1.5.1. When refreshing an IMMV, pg_ivm executes functions without specifying schema names. Under certain conditions, pg_ivm may be tricked to execute unexpected functions from other schemas with the IMMV owner's privilege. If this vulnerability is exploited, an unexpected function provided by an attacker may be executed with the privilege of the materialized view owner.
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Analysis
by VulDB Data Team • 10/13/2025
The CVE-2023-23554 vulnerability represents a critical uncontrolled search path element weakness in the pg_ivm extension for PostgreSQL databases. This vulnerability specifically affects versions prior to 1.5.1 and stems from the improper handling of schema resolution during materialized view refresh operations. The issue manifests when pg_ivm executes functions without explicitly specifying schema names, creating an environment where the database engine's search path resolution can be manipulated by malicious actors. This flaw aligns with CWE-427 Uncontrolled Search Path Element, which describes how applications that do not properly control the search path can be exploited to execute unintended code. The vulnerability is particularly concerning in multi-tenant database environments where different users may have materialized views with varying privilege levels, as it allows for privilege escalation through function execution manipulation.
The technical implementation of this vulnerability occurs during the refresh process of an IMMV (Incremental Materialized View) within the pg_ivm extension. When the system attempts to refresh a materialized view, it calls upon underlying functions without explicitly defining which schema these functions reside in. This design flaw creates an opportunity for attackers to place malicious functions in schemas that appear earlier in the database's search path, effectively hijacking the execution flow. The database engine will resolve the function call to the first matching function found in the search path, regardless of the intended target. This behavior is consistent with the principles outlined in the ATT&CK framework under T1068 Privilege Escalation, where adversaries exploit system weaknesses to gain elevated privileges. The vulnerability specifically targets the schema resolution mechanism, allowing an attacker to execute arbitrary code with the privileges of the materialized view owner, potentially enabling data exfiltration, modification, or complete system compromise.
The operational impact of CVE-2023-23554 extends beyond simple privilege escalation to encompass potential data integrity breaches and unauthorized access to sensitive information. When exploited, this vulnerability allows attackers to execute malicious functions with elevated privileges, potentially leading to complete database compromise. The attack vector becomes particularly dangerous in environments where database administrators create materialized views with high-privilege accounts, as these views may be used to access sensitive data or perform administrative operations. Organizations using pg_ivm versions prior to 1.5.1 face significant risk, especially in environments where multiple schemas exist with different privilege levels. The vulnerability can be exploited by attackers who have access to the database at any level, making it a serious concern for both internal and external threat actors. This weakness directly violates the principle of least privilege and can enable attackers to bypass normal access controls, potentially leading to data loss, corruption, or unauthorized system modifications.
Mitigation strategies for CVE-2023-23554 primarily focus on upgrading to pg_ivm version 1.5.1 or later, which includes proper schema qualification for function calls. Organizations should implement immediate patch management protocols to address this vulnerability across all affected systems. Additionally, database administrators should review and restrict schema search paths, ensuring that attacker-controlled schemas do not appear in positions that could be exploited. The implementation of proper function qualification through explicit schema names during materialized view operations is essential for preventing this class of vulnerability. Security monitoring should include detection of unusual function execution patterns and privilege escalation attempts. Database access controls should be reviewed to ensure that materialized views are not created with unnecessary elevated privileges. Organizations should also consider implementing database activity monitoring tools that can detect anomalous execution patterns consistent with privilege escalation attempts. The vulnerability highlights the importance of following secure coding practices and maintaining up-to-date security patches, as this issue could have been prevented through proper schema resolution implementation. Regular security assessments and vulnerability scanning should include checks for similar uncontrolled search path vulnerabilities in other database extensions and applications.