CVE-2013-4033 in DB2
Summary
by MITRE
IBM DB2 and DB2 Connect 9.7 through FP8, 9.8 through FP5, 10.1 through FP2, and 10.5 through FP1 allow remote authenticated users to execute DML statements by leveraging EXPLAIN authority.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 05/21/2021
This vulnerability exists in IBM DB2 and DB2 Connect database systems across multiple versions including 9.7 through FP8, 9.8 through FP5, 10.1 through FP2, and 10.5 through FP1. The flaw represents a significant authorization bypass issue that allows remote authenticated users to execute Data Manipulation Language statements through improper privilege handling. The vulnerability specifically leverages the EXPLAIN authority, which should typically only provide query execution plans and performance analysis information. However, in this case, the system fails to properly validate or restrict access when users possess EXPLAIN privileges, enabling them to escalate their privileges and execute arbitrary DML operations.
The technical implementation of this vulnerability stems from inadequate privilege separation within the database engine's authorization framework. When users possess EXPLAIN authority, they should be restricted to query analysis functions only, but the flaw allows these users to manipulate the underlying database through DML operations. This represents a classic case of privilege escalation where a seemingly benign administrative function becomes a vector for more dangerous database operations. The vulnerability aligns with CWE-269 Privilege Issues, specifically involving improper privileges for database operations and inadequate access control enforcement.
From an operational impact perspective, this vulnerability creates a serious security risk for database environments where multiple users have varying levels of access. Remote authenticated users can potentially modify, delete, or insert data without proper authorization, leading to data integrity compromises, unauthorized data access, and potential system compromise. The remote nature of the attack means that attackers do not need physical access to the database server, making the vulnerability particularly dangerous in networked environments. This flaw directly impacts the CIA triad by compromising confidentiality through unauthorized data access and integrity through unauthorized data modification.
The vulnerability demonstrates how database administration functions can inadvertently create security gaps when privilege models are not properly implemented. Attackers can exploit this by first establishing a legitimate database connection with EXPLAIN privileges and then using this access to execute DML statements that should normally be restricted to users with higher privileges. This attack pattern aligns with ATT&CK technique T1078 Valid Accounts, as it leverages legitimate user credentials to perform unauthorized actions. The exploitation requires minimal complexity but can result in substantial damage to database systems, making it a high-risk vulnerability for organizations relying on IBM DB2 implementations.
Organizations should immediately apply the relevant security patches provided by IBM for the affected versions to address this vulnerability. The recommended mitigation involves ensuring that users with EXPLAIN authority are properly restricted from executing DML operations, implementing additional monitoring for suspicious database activities, and reviewing privilege assignments to minimize the risk of unauthorized escalation. Database administrators should also consider implementing network segmentation and access controls to limit the potential impact of such vulnerabilities, while maintaining proper audit logging to detect any unauthorized database activities that may indicate exploitation attempts.