CVE-2002-1895 in Tomcat
Summary
by MITRE
The servlet engine in Jakarta Apache Tomcat 3.3 and 4.0.4, when using IIS and the ajp1.3 connector, allows remote attackers to cause a denial of service (crash) via a large number of HTTP GET requests for an MS-DOS device such as AUX, LPT1, CON, or PRN.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 06/13/2017
The vulnerability identified as CVE-2002-1895 represents a significant denial of service weakness in the Jakarta Apache Tomcat servlet engine versions 3.3 and 4.0.4 when integrated with Microsoft Internet Information Server using the ajp1.3 connector protocol. This flaw stems from the improper handling of specific MS-DOS device names within HTTP GET requests, creating a condition where legitimate service requests can be exploited to crash the application server. The vulnerability specifically targets the interaction between Tomcat's servlet engine and IIS through the AJP (Apache JServ Protocol) version 1.3 connector, which serves as a communication bridge between the web server and the application server. When malicious actors submit a large volume of HTTP GET requests containing these reserved MS-DOS device names, the Tomcat server fails to properly process these requests, leading to system instability and eventual service disruption.
The technical root cause of this vulnerability lies in the insufficient input validation and error handling mechanisms within Tomcat's request processing pipeline. When the servlet engine encounters requests for MS-DOS device names such as AUX, LPT1, CON, or PRN, it attempts to resolve these paths through the operating system's file handling mechanisms. These device names are reserved in the MS-DOS and Windows operating systems for hardware devices and special system functions, making them invalid for normal file operations. The Tomcat server's inability to properly intercept and reject these malformed requests results in a cascade of processing errors that ultimately lead to memory corruption or resource exhaustion. This issue is particularly dangerous because it can be exploited through simple HTTP GET requests without requiring authentication or advanced exploitation techniques, making it accessible to any remote attacker with network access to the vulnerable system.
The operational impact of this vulnerability extends beyond simple service disruption to encompass potential business continuity risks and system reliability concerns for organizations relying on affected Tomcat versions. Attackers can effectively render web applications unavailable by flooding the server with these specific request patterns, causing the application server to crash and requiring manual intervention for recovery. The vulnerability demonstrates a classic weakness in the principle of least privilege and proper input sanitization, as the system fails to validate request parameters against known problematic inputs before attempting to process them. Organizations using this configuration face significant risk of operational downtime, especially during peak traffic periods when the denial of service attack can compound existing system load. The attack vector is particularly concerning because it leverages the standard HTTP protocol and does not require specialized tools or deep technical knowledge, making it accessible to a broad range of threat actors.
Mitigation strategies for CVE-2002-1895 focus on both immediate defensive measures and long-term architectural improvements. Organizations should immediately upgrade to patched versions of Apache Tomcat, specifically versions 3.3.1 and 4.1.12 or later, which contain the necessary fixes to properly handle these reserved device names. Network-level protections such as intrusion prevention systems and web application firewalls can be configured to detect and block requests containing these specific MS-DOS device names before they reach the Tomcat server. Additionally, administrators should implement request rate limiting and connection throttling mechanisms to prevent abuse of the vulnerability through massive request floods. The fix implemented in later versions addresses the underlying CWE-20 issue of input validation weakness by ensuring that all incoming requests are properly sanitized and validated against a whitelist of acceptable characters and paths. Organizations should also consider implementing monitoring and alerting systems to detect unusual patterns of requests that might indicate exploitation attempts, aligning with the ATT&CK technique of command and control through network traffic analysis. System administrators should conduct regular security assessments to identify and remediate similar vulnerabilities in their application server configurations, emphasizing the importance of proper input validation and error handling in preventing denial of service attacks.