CVE-2011-1033 in Informix Dynamic Server
Summary
by MITRE
Stack-based buffer overflow in oninit in IBM Informix Dynamic Server (IDS) 11.50 allows remote attackers to execute arbitrary code via crafted arguments in the USELASTCOMMITTED session environment option in a SQL SET ENVIRONMENT statement.
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Analysis
by VulDB Data Team • 04/03/2017
The vulnerability identified as CVE-2011-1033 represents a critical stack-based buffer overflow flaw within IBM Informix Dynamic Server version 11.50. This issue specifically affects the oninit component which serves as the initialization process for the database system. The flaw manifests when processing SQL SET ENVIRONMENT statements that contain crafted arguments in the USELASTCOMMITTED session environment option, creating a potential pathway for remote code execution. The vulnerability resides in the improper handling of user-supplied input during the database initialization phase, where insufficient bounds checking allows malicious data to overwrite adjacent memory locations on the stack.
The technical exploitation of this vulnerability occurs through the manipulation of session environment options within SQL commands, specifically targeting the USELASTCOMMITTED parameter. When a remote attacker crafts malicious arguments for this environment option and executes them through a SQL SET ENVIRONMENT statement, the oninit process fails to validate the input length properly. This validation failure results in a buffer overflow condition where the excessive input data overflows the allocated stack buffer, potentially corrupting the return address of the calling function and allowing an attacker to redirect execution flow. The flaw demonstrates characteristics consistent with CWE-121 Stack-based Buffer Overflow, where insufficient bounds checking permits memory corruption that can be leveraged for arbitrary code execution.
The operational impact of this vulnerability extends beyond simple data compromise, as it provides attackers with complete system control when successfully exploited. Remote attackers can execute arbitrary code with the privileges of the database service account, potentially leading to full system compromise, data exfiltration, or disruption of database services. The vulnerability affects organizations running IBM Informix Dynamic Server 11.50, making it particularly concerning for enterprises that rely on this database platform for critical business operations. The remote nature of the attack means that exploitation can occur from any network location without requiring physical access to the system, significantly expanding the attack surface and threat landscape.
Mitigation strategies for CVE-2011-1033 should focus on immediate patching of the affected IBM Informix Dynamic Server version 11.50 to address the buffer overflow condition in the oninit component. Organizations should implement network segmentation and access controls to limit exposure of database systems to untrusted networks, following ATT&CK technique T1190 for exploiting public-facing applications. Additionally, monitoring for suspicious SQL SET ENVIRONMENT statements and implementing input validation controls can help detect and prevent exploitation attempts. The remediation process should include comprehensive testing of patched systems to ensure that the vulnerability is fully resolved without introducing regressions in database functionality, while also updating security monitoring tools to detect potential exploitation attempts that may leverage similar patterns to those described in the vulnerability analysis.