CVE-2008-3959 in DB2
Summary
by MITRE
IBM DB2 UDB 8.1 before FixPak 16, 8.2 before FixPak 9, and 9.1 before FixPak 4a allows remote attackers to cause a denial of service (instance crash) via a crafted SQLJRA packet within a CONNECT/ATTACH data stream that simulates a V7 client connect/attach request.
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Analysis
by VulDB Data Team • 08/02/2021
IBM DB2 Universal Database versions 8.1 through 9.1 suffered from a critical denial of service vulnerability that enabled remote attackers to crash database instances through carefully crafted SQLJRA packets. This vulnerability specifically targeted the database's handling of CONNECT/ATTACH data streams that simulate V7 client connections, where the malformed SQLJRA packet triggered an unhandled exception in the database engine's connection processing logic. The flaw existed in the protocol parsing mechanisms that failed to properly validate incoming connection requests, particularly when processing legacy V7 client compatibility modes. The vulnerability mapped to CWE-121, which describes buffer overflow conditions, though the actual manifestation occurred through improper input validation rather than direct buffer manipulation. Attackers could exploit this weakness by sending a specially crafted packet sequence that appeared to be a legitimate V7 client connection attempt but contained malformed SQLJRA data that caused the database instance to terminate unexpectedly. This vulnerability fell under the ATT&CK technique T1499.004, specifically targeting service availability through denial of service attacks against database services. The impact extended beyond simple service interruption, as database crashes could result in data loss, transaction rollbacks, and extended downtime for applications dependent on the affected database instances. Organizations running these vulnerable versions faced significant operational risks, particularly in environments where database availability was critical for business operations. The vulnerability was particularly concerning because it required no authentication credentials to exploit, making it a high-risk issue for publicly accessible database servers. The root cause stemmed from insufficient input validation in the database's legacy protocol handling code, where the system failed to properly sanitize connection parameters before processing them. This weakness allowed attackers to bypass normal security controls and directly target the database engine's connection management subsystem. The vulnerability was addressed through IBM's FixPak updates, which introduced proper input validation and error handling for SQLJRA packet processing. Organizations needed to apply these patches promptly to mitigate the risk of exploitation, as the vulnerability could be exploited by automated scanning tools to identify and compromise vulnerable systems. The attack vector demonstrated the importance of proper protocol implementation and input validation in database systems, particularly when maintaining backward compatibility with legacy client protocols. Database administrators should have implemented network segmentation and access controls to limit exposure, while monitoring systems could detect unusual connection patterns that might indicate exploitation attempts. The vulnerability highlighted the risks associated with maintaining legacy protocol support in production database environments, as these compatibility layers often contained unpatched security flaws. Organizations should have conducted thorough vulnerability assessments to identify all instances running affected versions and prioritized patching based on risk exposure and business impact considerations. The incident underscored the necessity of maintaining current security patches for enterprise database systems and implementing proper vulnerability management processes to prevent similar issues from affecting critical infrastructure components.