CVE-2002-1942 in Xitami
Summary
by MITRE
Imatix Xitami 2.5 b5 does not properly terminate certain Keep-Alive connections that have been broken or closed early, which allows remote attackers to cause a denial of service (crash) via a large number of concurrent sessions.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 07/06/2024
The vulnerability identified as CVE-2002-1942 affects the Imatix Xitami web server version 2.5 build 5, representing a critical denial of service weakness that exploits improper connection handling mechanisms. This flaw resides in the server's HTTP implementation where it fails to properly manage Keep-Alive connection states when clients disconnect prematurely or when connections become broken during active sessions. The issue specifically manifests when multiple concurrent sessions are established and then terminated unexpectedly, creating a scenario where the server maintains references to these abandoned connections in its internal connection management structures.
The technical nature of this vulnerability stems from inadequate state management within the Xitami web server's connection handling routines. When clients establish Keep-Alive connections to the server and then close them prematurely without proper HTTP protocol termination sequences, the server's connection tracking mechanism fails to properly release associated resources or update connection states. This results in a memory leak scenario where connection descriptors remain allocated in the server's memory space, eventually leading to resource exhaustion. The vulnerability becomes particularly dangerous when attackers can establish a large number of concurrent sessions that are then terminated early, amplifying the resource consumption effect exponentially.
From an operational perspective, this vulnerability creates a significant risk for web server availability and system stability. An attacker capable of establishing multiple concurrent connections to the Xitami server and then closing them prematurely can systematically consume server resources until the system becomes unresponsive or crashes entirely. The impact extends beyond simple service disruption as the server may become completely unavailable to legitimate users, potentially affecting business operations and customer access to web applications hosted on the affected server. This type of denial of service attack can be executed with relatively simple tools and does not require sophisticated exploitation techniques, making it particularly dangerous in production environments.
The vulnerability aligns with CWE-400, which categorizes improper resource management as a common weakness in software systems, specifically addressing the failure to properly handle resource cleanup in network applications. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network denial of service attacks, and represents a classic example of resource exhaustion as a method for achieving system disruption. The attack vector requires only network connectivity to the target server and can be automated to establish multiple concurrent connections, making it suitable for both targeted attacks against specific systems and broader scanning campaigns. Organizations should implement connection rate limiting and connection timeout configurations as immediate mitigations, while the most effective solution remains upgrading to a patched version of the Xitami server software that properly handles connection state management and resource cleanup for broken or prematurely terminated Keep-Alive sessions.