CVE-2002-0905 in Informix
Summary
by MITRE
Buffer overflow in sqlexec for Informix SE-7.25 allows local users to gain root privileges via a long INFORMIXDIR environment variable.
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Analysis
by VulDB Data Team • 11/23/2024
The vulnerability identified as CVE-2002-0905 represents a critical buffer overflow flaw within the sqlexec component of Informix Single Engine version 7.25. This issue specifically affects the handling of the INFORMIXDIR environment variable, which serves as a crucial configuration parameter for the Informix database system. The buffer overflow occurs when the system processes an excessively long INFORMIXDIR value, creating a condition where memory beyond the allocated buffer space becomes overwritten. This flaw exists at the intersection of improper input validation and inadequate buffer management within the database execution environment.
The technical exploitation of this vulnerability leverages the fact that sqlexec, a component responsible for executing SQL commands within the Informix environment, fails to properly validate the length of the INFORMIXDIR environment variable before processing it. When a local user provides a maliciously long value for this environment variable, the system's memory allocation routine does not adequately check bounds, allowing the overflow to occur. This particular flaw is classified under CWE-121 as a stack-based buffer overflow, where the overflow corrupts the program's execution flow and can be manipulated to execute arbitrary code. The vulnerability specifically targets the privilege escalation mechanism, as the sqlexec component typically runs with elevated privileges to perform database operations, making the potential for privilege escalation particularly dangerous.
The operational impact of this vulnerability extends beyond simple local privilege escalation, as it provides attackers with root-level access to systems running vulnerable Informix installations. This access level allows for complete system compromise, enabling unauthorized data access, modification, or deletion, as well as the installation of persistent backdoors or malware. The vulnerability is particularly concerning in enterprise environments where Informix databases often handle sensitive corporate data, making the potential for data breaches and system compromise significant. The attack vector requires only local system access, meaning that any user with login privileges can exploit this vulnerability, potentially leading to insider threat scenarios or compromised accounts being leveraged for broader attacks.
Mitigation strategies for CVE-2002-0905 should prioritize immediate patching of affected systems with vendor-supplied security updates. Organizations should also implement environment variable length validation policies and monitor system logs for unusual INFORMIXDIR values. The principle of least privilege should be enforced by ensuring that sqlexec and related database components run with minimal necessary permissions rather than root privileges. Additionally, system administrators should consider implementing intrusion detection systems to monitor for potential exploitation attempts and establish baseline configurations that prevent overly long environment variables from being processed. This vulnerability aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation' and demonstrates the importance of proper input validation and memory management in preventing such critical security flaws.