CVE-2003-0827 in DB2 Universal Database
Summary
by MITRE
The DB2 Discovery Service for IBM DB2 before FixPak 10a allows remote attackers to cause a denial of service (crash) via a long packet to UDP port 523.
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Analysis
by VulDB Data Team • 06/26/2019
The vulnerability identified as CVE-2003-0827 affects the DB2 Discovery Service component within IBM DB2 database management systems prior to FixPak 10a. This particular service operates on UDP port 523 and serves as a mechanism for database discovery and network enumeration. The flaw represents a classic buffer overflow condition that occurs when the service receives malformed network packets exceeding predetermined size limits. The vulnerability stems from insufficient input validation and boundary checking within the packet processing routine, allowing malicious actors to craft specially constructed UDP packets that trigger memory corruption. This type of vulnerability aligns with CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking permits memory access beyond allocated buffers. The Discovery Service functionality was designed to facilitate network discovery by responding to queries from other database instances, but the lack of proper packet size validation creates an attack surface that can be exploited by remote adversaries.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the overall database infrastructure. When an attacker sends a long packet to UDP port 523, the DB2 Discovery Service process crashes and terminates unexpectedly, resulting in a denial of service condition that affects database availability. The crash occurs because the service attempts to process the oversized packet without proper bounds checking, leading to memory corruption that causes the application to terminate. This behavior can be leveraged in distributed denial of service attacks where multiple systems target the vulnerable service simultaneously, potentially causing cascading failures across database networks. From an attacker perspective, this vulnerability represents a low-effort, high-impact method for disrupting database operations, as it requires minimal technical expertise to exploit and can be automated using simple network packet crafting tools. The vulnerability also aligns with ATT&CK technique T1499.004, which describes network denial of service attacks targeting database services.
Mitigation strategies for CVE-2003-0827 primarily involve applying the appropriate IBM FixPak updates that address the buffer overflow condition in the DB2 Discovery Service. Organizations should immediately implement FixPak 10a or later versions that contain the necessary code modifications to properly validate packet sizes and implement proper boundary checking. Network-level mitigations include implementing firewall rules to block UDP traffic on port 523 from untrusted networks, effectively preventing external exploitation attempts. Additionally, organizations can disable the Discovery Service entirely if it is not required for their database operations, reducing the attack surface through service hardening. System administrators should also implement monitoring solutions to detect unusual packet patterns targeting UDP port 523, which can serve as early warning indicators of exploitation attempts. The vulnerability demonstrates the critical importance of input validation in network services and the potential for remote code execution through seemingly benign denial of service conditions. This case study reinforces industry best practices for secure coding, particularly the need for robust error handling and boundary checking in network-facing applications. Organizations should also conduct regular vulnerability assessments to identify similar conditions in other database services and network components that may exhibit similar buffer overflow characteristics. The remediation process should include comprehensive testing to ensure that the applied fixes do not introduce compatibility issues with existing database operations while maintaining the security posture against similar vulnerabilities in the database ecosystem.