CVE-2018-1802 in DB2
Summary
by MITRE
IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, and 11.1 binaries load shared libraries from an untrusted path potentially giving low privilege user full access to the DB2 instance account by loading a malicious shared library. IBM X-Force ID: 149640.
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Analysis
by VulDB Data Team • 06/05/2023
This vulnerability resides in IBM DB2 database management systems across multiple versions including 9.7, 10.1, 10.5, and 11.1 for Linux, UNIX, and Windows platforms. The core issue stems from improper handling of shared library loading mechanisms where the database server binaries fail to validate or restrict the paths from which shared libraries are loaded. This design flaw creates a critical security weakness that allows local attackers with minimal privileges to escalate their access rights significantly. The vulnerability manifests when the DB2 instance loads shared libraries from directories that are not properly secured or validated, enabling malicious actors to place crafted shared libraries in these locations and subsequently gain full control over the DB2 instance account. This represents a classic privilege escalation vulnerability that directly violates security principles of least privilege and secure coding practices. The flaw aligns with CWE-426 which addresses the dangerous use of external loadable libraries and can be categorized under ATT&CK technique T1068 which covers privilege escalation through malicious library loading.
The technical implementation of this vulnerability exploits the inherent trust model within the DB2 installation where certain directories are assumed to be safe for library loading without proper validation. When DB2 processes requests, it may dynamically load shared libraries from system paths that are not properly secured against unauthorized modifications. Attackers can leverage this by placing malicious shared libraries in these trusted directories, causing the DB2 instance to load and execute the malicious code with the elevated privileges of the DB2 service account. The impact is severe as the DB2 instance typically runs with high privileges to perform database operations, and successful exploitation grants attackers complete control over the database instance, potentially leading to data theft, modification, or complete system compromise. This vulnerability directly undermines the principle of secure library loading and represents a failure in proper input validation and path resolution mechanisms.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete database instance compromise. Once an attacker successfully loads a malicious shared library, they gain the ability to execute arbitrary code within the DB2 process context, which may include accessing sensitive database information, modifying database structures, or even using the compromised DB2 instance as a pivot point for further attacks within the network. The vulnerability affects organizations running IBM DB2 in production environments where local access might be available to untrusted users or where privilege separation is not properly enforced. Organizations may face significant data exposure risks as the compromised DB2 instance could contain confidential information, financial data, or personal identifiable information that is protected by various compliance regulations. The attack vector requires local access and low privilege levels, making it particularly dangerous in environments where least privilege principles are not strictly enforced or where user access controls are insufficiently configured.
Mitigation strategies for this vulnerability require immediate patching of affected IBM DB2 versions through official IBM security updates and fixes. Organizations should also implement proper path validation and library loading restrictions within their DB2 configurations, ensuring that shared library paths are properly secured and that only trusted libraries are loaded. System administrators should conduct thorough security audits of DB2 installation directories and verify that no unauthorized modifications have been made to library loading paths. Additional defensive measures include implementing proper file system permissions on DB2 installation directories, monitoring for unusual library loading activities, and ensuring that DB2 instances run with minimal required privileges. Network segmentation and access controls should be enforced to limit local access to DB2 systems, while regular security assessments should be performed to identify and remediate similar path traversal and library loading vulnerabilities across the organization's database infrastructure. Organizations should also consider implementing application whitelisting solutions to prevent unauthorized shared library execution and establish proper monitoring and alerting for suspicious library loading activities within database processes.