CVE-2005-0245 in PostgreSQL
Summary
by MITRE • 01/25/2023
Buffer overflow in gram.y for PostgreSQL 8.0.0 and earlier may allow attackers to execute arbitrary code via a large number of arguments to a refcursor function (gram.y), which leads to a heap-based buffer overflow, a different vulnerability than CVE-2005-0247.
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Analysis
by VulDB Data Team • 07/05/2025
The vulnerability described in CVE-2005-0245 represents a critical heap-based buffer overflow flaw within the PostgreSQL database management system version 8.0.0 and earlier. This vulnerability specifically affects the grammar parsing component known as gram.y which is responsible for processing SQL statements and function calls within the database engine. The flaw occurs when the system processes a refcursor function with an excessive number of arguments, creating a condition where memory allocated for argument processing exceeds its designated bounds. This type of vulnerability falls under CWE-121, which categorizes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The vulnerability is particularly concerning because it exists within the core parsing logic of the database engine, making it accessible through normal database operations.
The technical execution of this vulnerability involves the exploitation of improper input validation within the PostgreSQL parser's handling of refcursor function arguments. When a malicious user submits a SQL statement containing a refcursor function with an unusually large number of parameters, the parser in gram.y fails to properly validate the argument count against allocated buffer sizes. This results in memory corruption that can be leveraged to overwrite critical program data or execution control structures. The heap-based nature of the overflow means that the corrupted memory locations are dynamically allocated during runtime, making the exploitation more complex but potentially more reliable than stack-based overflows. The vulnerability demonstrates a classic lack of input sanitization and bounds checking that is common in legacy database systems where security considerations were not adequately integrated into the parsing architecture.
The operational impact of this vulnerability extends beyond simple code execution, as successful exploitation could lead to complete system compromise and unauthorized access to sensitive database information. An attacker who successfully exploits this vulnerability could potentially execute arbitrary code with the privileges of the database process, which typically runs with elevated permissions on the host system. This could result in data theft, database corruption, privilege escalation to system-level access, and potential lateral movement within the network infrastructure. The vulnerability affects organizations using PostgreSQL versions prior to 8.0.1, representing a significant risk for any enterprise relying on these older database versions. The specific targeting of the refcursor function suggests that this vulnerability could be exploited through normal database user interactions, making it particularly dangerous as it does not require specialized attack vectors or unusual database configurations.
Organizations should prioritize immediate remediation by upgrading to PostgreSQL version 8.0.1 or later, which contains the necessary patches to address this buffer overflow condition. The mitigation strategy should include comprehensive vulnerability scanning to identify systems running affected PostgreSQL versions and implementing proper access controls to limit database user privileges. Additionally, monitoring systems should be configured to detect unusual patterns in database function calls that might indicate attempted exploitation of this vulnerability. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1059.007, which covers the use of database commands for execution, and T1190, which addresses the exploitation of vulnerabilities in database applications. The remediation approach should also include regular security assessments of database systems to identify similar parsing vulnerabilities that may exist in other components of the database engine or related applications.