CVE-2005-0942 in Adaptive Server Enterprise
Summary
by MITRE
The XP Server process (xp_server) in Sybase Adaptive Server Enterprise (ASE) XP Server 12.x before 12.5.3 ESD#1 allows attackers to cause a denial of service (process crash) via malformed data sent to the XP Server TCP port.
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Analysis
by VulDB Data Team • 06/01/2019
The vulnerability described in CVE-2005-0942 represents a critical denial of service weakness within Sybase Adaptive Server Enterprise's XP Server component. This flaw affects versions 12.x of the ASE XP Server prior to 12.5.3 ESD#1, specifically targeting the xp_server process that handles external procedure calls. The vulnerability stems from insufficient input validation mechanisms within the TCP port communication layer, where the xp_server process fails to properly sanitize or reject malformed data packets. When attackers send carefully crafted malformed data to the XP Server TCP port, the process becomes vulnerable to crash conditions that result in complete service interruption. This type of vulnerability falls under the category of improper input validation as classified by CWE-20, which is a fundamental weakness in software design that allows malicious inputs to disrupt normal application operations. The vulnerability exists at the network protocol handling level where the system does not implement adequate bounds checking or data integrity verification before processing incoming TCP connections.
The operational impact of this vulnerability extends beyond simple service disruption as it can be exploited to create sustained denial of service conditions that affect database availability and business continuity. When the xp_server process crashes due to malformed data, it typically requires manual intervention to restart the service, potentially causing extended downtime for database operations. This vulnerability particularly affects enterprise environments that rely heavily on Sybase ASE for critical business applications, where database unavailability can result in significant financial losses and operational disruption. The attack vector is relatively straightforward as it only requires network access to the targeted TCP port, making it accessible to remote attackers without requiring elevated privileges or specialized access. From an attacker perspective, this vulnerability aligns with ATT&CK technique T1499.004 which involves network disruption attacks targeting availability, and represents a classic example of how protocol-level flaws can be exploited to create system instability.
The technical exploitation of this vulnerability demonstrates the importance of robust input validation and error handling in network services. The xp_server process in Sybase ASE was designed to handle external procedure calls through TCP connections, but the implementation lacked proper data sanitization mechanisms that would prevent malformed packets from causing process termination. This flaw indicates a failure in the defensive programming practices that should include input validation, exception handling, and resource management. Organizations running affected versions of Sybase ASE should immediately implement the vendor-provided patch that addresses this specific vulnerability in version 12.5.3 ESD#1. Additional mitigations include implementing network segmentation to limit access to the XP Server TCP port, deploying intrusion detection systems to monitor for suspicious traffic patterns, and configuring firewall rules to restrict access to only trusted sources. The vulnerability also underscores the necessity of regular security updates and the importance of maintaining current patches for enterprise database systems. Organizations should conduct vulnerability assessments to identify other potentially affected components and ensure that all database systems are properly maintained with the latest security patches to prevent similar exploitation vectors from compromising system availability and integrity.