CVE-2002-1402 in PostgreSQL
Summary
by MITRE
Buffer overflows in the (1) TZ and (2) SET TIME ZONE enivronment variables for PostgreSQL 7.2.1 and earlier allow local users to cause a denial of service and possibly execute arbitrary code.
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Analysis
by VulDB Data Team • 09/06/2025
The vulnerability identified as CVE-2002-1402 represents a critical buffer overflow issue affecting PostgreSQL database systems version 7.2.1 and earlier. This security flaw manifests specifically within the handling of two environment variables: TZ and SET TIME ZONE. The vulnerability stems from insufficient input validation and bounds checking when processing these time zone related parameters, creating an exploitable condition that can be leveraged by local attackers to compromise system integrity.
The technical implementation of this vulnerability occurs when the PostgreSQL server processes time zone information through the TZ environment variable or the SET TIME ZONE command. When an attacker provides maliciously crafted input exceeding the allocated buffer space, the system experiences a buffer overflow condition that can corrupt adjacent memory locations. This memory corruption typically results in application crashes or can be manipulated to redirect program execution flow, potentially allowing arbitrary code execution with the privileges of the PostgreSQL service account. The vulnerability is classified as a buffer overflow under CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as local attackers with minimal privileges can exploit the condition to gain elevated system access. The attack surface is particularly concerning because it requires only local system access, making it accessible to users who have basic login privileges on the target system. Once exploited, the vulnerability can lead to complete system compromise, data theft, or persistent backdoor access. The vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' through local system exploits that leverage buffer overflow conditions to execute malicious code with higher privileges.
Mitigation strategies for CVE-2002-1402 should prioritize immediate patching of affected PostgreSQL installations to version 7.2.2 or later, which contains the necessary fixes for the buffer overflow conditions. System administrators should also implement proper input validation and bounds checking for all environment variables, particularly those related to time zone settings. Additionally, deploying application whitelisting controls and restricting local user privileges can help minimize the potential impact of such vulnerabilities. Organizations should consider implementing network segmentation and monitoring for unusual database access patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of maintaining up-to-date database software and implementing comprehensive security practices to prevent local privilege escalation attacks that can compromise entire database systems.