CVE-2003-0290 in EServ
Summary
by MITRE
Memory leak in eServ 2.9x allows remote attackers to cause a denial of service (memory exhaustion) via a large number of connections, whose memory is not freed when the connection is terminated.
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Analysis
by VulDB Data Team • 08/20/2025
The vulnerability identified as CVE-2003-0290 represents a critical memory management flaw in eServ 2.9x web server software that exposes systems to remote denial of service attacks. This memory leak occurs when the application fails to properly release allocated memory resources upon connection termination, creating a gradual accumulation of memory consumption that eventually leads to system instability and service unavailability. The flaw specifically targets the connection handling mechanism within the web server's architecture, where each established connection consumes memory that should be reclaimed but remains allocated indefinitely.
The technical implementation of this vulnerability stems from improper resource cleanup procedures within the eServ software's network connection management code. When remote attackers establish numerous concurrent connections to the vulnerable server, each connection triggers memory allocation for buffering, session management, and protocol handling components. However, upon connection termination, the application's memory deallocation routines fail to execute properly, resulting in memory fragments that remain in the system heap. This behavior constitutes a classic memory leak pattern that aligns with CWE-401, which specifically addresses improper resource management and memory leaks in software applications. The vulnerability demonstrates a fundamental flaw in the application's resource lifecycle management where allocated memory is not properly returned to the system's available memory pool.
The operational impact of this vulnerability extends beyond simple service disruption to encompass broader system stability concerns that affect network availability and performance. As attackers continue to establish connections, the memory exhaustion process accelerates, potentially leading to complete system crashes or severe performance degradation that makes the server unusable for legitimate users. This type of denial of service attack operates at the system level rather than application level, making it particularly dangerous as it can affect not just the web server functionality but potentially the entire hosting environment. The vulnerability creates an attacker-controlled memory consumption pattern that can be amplified through automated tools, enabling sustained denial of service attacks that are difficult to distinguish from legitimate traffic spikes.
Mitigation strategies for CVE-2003-0290 require both immediate and long-term approaches to address the underlying memory management issues within eServ 2.9x installations. System administrators should implement connection rate limiting and monitoring mechanisms to detect abnormal connection patterns that may indicate exploitation attempts, while also establishing memory usage alerts to proactively identify memory exhaustion conditions. The most effective long-term solution involves upgrading to patched versions of eServ software that properly implement memory deallocation routines, ensuring that all allocated resources are correctly freed upon connection termination. Additionally, implementing network-level protections such as firewalls with connection tracking capabilities can help limit the number of concurrent connections and provide additional defense-in-depth measures against such attacks. This vulnerability demonstrates the importance of proper resource management in server applications and aligns with ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion, highlighting the need for robust memory management practices in network services to prevent exploitation by adversaries seeking to disrupt system availability.