CVE-2018-1857 in DB2
Summary
by MITRE
IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 11.1 could allow a user to bypass FGAC control and gain access to data they shouldn't be able to see. IBM X-Force ID: 151155.
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Analysis
by VulDB Data Team • 06/05/2023
The vulnerability identified as CVE-2018-1857 affects IBM DB2 for Linux, UNIX and Windows including the DB2 Connect Server version 11.1, representing a significant security flaw that undermines the database's fine-grained access control mechanisms. This issue stems from a weakness in the database's authorization framework that allows authenticated users to circumvent the Fine-Grained Access Control (FGAC) policies that are designed to restrict data access based on user roles and permissions. The flaw specifically targets the implementation of row-level security controls that should prevent unauthorized data exposure, creating a pathway for privilege escalation and data leakage.
The technical nature of this vulnerability resides in how IBM DB2 processes access control decisions when users attempt to query database objects that are protected by FGAC policies. The flaw enables attackers to bypass the normal access control checks that should validate whether a user has proper authorization to view specific rows or columns within database tables. This occurs through a manipulation of query execution paths or by exploiting inconsistencies in how access control decisions are evaluated during query processing. The vulnerability essentially allows an authenticated user to craft queries or leverage existing database features in ways that circumvent the intended access restrictions, potentially exposing sensitive data that should remain protected.
The operational impact of this vulnerability is substantial as it directly compromises the confidentiality and integrity of data stored within IBM DB2 environments. Organizations relying on FGAC for protecting sensitive information such as financial records, personal data, or proprietary business information face significant risk of unauthorized data access. The vulnerability can be exploited by both internal users with legitimate database access and external attackers who have obtained valid credentials, making it particularly dangerous in environments where privileged accounts are compromised. This flaw undermines the fundamental security model of the database system and could lead to regulatory compliance violations, financial losses, and reputational damage when sensitive data is accessed without proper authorization.
Organizations should implement immediate mitigations including applying the relevant IBM security patches and updates that address this specific vulnerability in the DB2 database software. System administrators should conduct comprehensive audits of existing FGAC policies and access controls to identify potential exploitation vectors, while also implementing additional monitoring mechanisms to detect anomalous database access patterns. The vulnerability aligns with CWE-284, which describes improper access control issues in software systems, and represents a clear violation of the principle of least privilege that should govern database access. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, as it allows users to bypass existing security controls and gain unauthorized access to protected data. Organizations should also consider implementing database activity monitoring solutions and regular security assessments to prevent exploitation of similar access control weaknesses in their database environments.