CVE-2020-4161 in DB2
Summary
by MITRE
IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 11.5 could allow an authenticated attacker to cause a denial of service due to incorrect handling of certain commands. IBM X-Force ID: 174341.
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Analysis
by VulDB Data Team • 04/01/2024
IBM DB2 version 11.5 running on Linux, UNIX, and Windows platforms including DB2 Connect Server contains a vulnerability that allows authenticated attackers to trigger a denial of service condition through improper handling of specific commands. This vulnerability stems from insufficient validation mechanisms within the database server's command processing pipeline, where certain malformed or specially crafted commands can cause the system to crash or become unresponsive. The flaw specifically manifests when the database engine encounters commands that should be properly rejected or handled gracefully, but instead results in system instability. Attackers who have valid authentication credentials can exploit this weakness to disrupt database services and potentially impact business operations. The vulnerability represents a critical security gap in the database server's input validation and error handling capabilities, where the system fails to properly sanitize command inputs before processing them. This issue falls under the category of improper input validation and can be classified as a CWE-20 vulnerability according to the Common Weakness Enumeration standards, specifically relating to the improper handling of inputs that could lead to system instability. The impact extends beyond simple service disruption as it can affect database availability and potentially compromise the integrity of ongoing transactions. From an operational standpoint, this vulnerability exposes organizations to significant risk as it allows attackers with legitimate access credentials to cause system-wide disruptions. The attack vector requires authentication, which limits the scope but does not eliminate the threat since privileged users with malicious intent could leverage this weakness. The vulnerability affects the core database engine functionality and can result in complete service outages that require manual intervention to restore normal operations. Organizations running IBM DB2 11.5 are particularly at risk as this version includes the vulnerable code paths that have not been patched in the affected releases. The issue aligns with several tactics in the MITRE ATT&CK framework including privilege escalation and denial of service, where the authenticated access requirement enables attackers to perform system-level disruptions. The lack of proper input sanitization creates an environment where command injection-like behaviors can occur, leading to unintended system states. This vulnerability demonstrates the importance of robust input validation in database systems and highlights the need for comprehensive security testing of command processing mechanisms. The IBM X-Force ID 174341 further validates the severity of this issue within the broader security community's threat landscape. Organizations should immediately implement security patches provided by IBM to address this vulnerability and prevent potential exploitation by unauthorized parties.
The technical implementation of this vulnerability involves the database server's command parser failing to properly validate or reject malformed commands that should be handled as errors. When an authenticated user submits commands that fall outside the expected parameter ranges or command structures, the system's error handling mechanism becomes overwhelmed or crashes, leading to the denial of service condition. This behavior represents a classic case of insufficient error handling and input validation where the system does not have adequate safeguards to prevent malformed inputs from causing system instability. The vulnerability exists in the command execution layer of the database engine where multiple command types can trigger the same problematic behavior. The affected systems must be patched with the appropriate IBM security updates to address the flawed command processing logic. Security teams should monitor for any unusual command execution patterns that might indicate exploitation attempts. The impact of this vulnerability can be severe as database services are fundamental to most enterprise operations, making this a high-priority security concern. Organizations should conduct thorough security assessments to determine if their systems are running vulnerable versions of IBM DB2 and implement proper access controls to limit the potential damage from authenticated attacks. The vulnerability also highlights the importance of maintaining current security patches and implementing comprehensive monitoring solutions to detect potential exploitation attempts in real-time.