CVE-2002-1857 in Webserver
Summary
by MITRE
jo! jo Webserver 1.0, when running on Windows, allows remote attackers to retrieve files in the WEB-INF directory, which contains Java class files and configuration information, via a request to the WEB-INF directory with a trailing dot ("WEB-INF.").
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Analysis
by VulDB Data Team • 09/01/2025
The vulnerability identified as CVE-2002-1857 affects the jo! jo Webserver version 1.0 running on Windows operating systems, representing a significant directory traversal flaw that exposes sensitive application components to unauthorized access. This weakness stems from improper input validation within the web server's handling of directory requests, specifically when processing paths that contain the WEB-INF directory structure. The vulnerability manifests when an attacker constructs a request containing a trailing dot character after the WEB-INF directory name, effectively bypassing normal access controls and permitting retrieval of Java class files and configuration information that should remain protected within the application's internal structure.
The technical exploitation of this vulnerability relies on the web server's inadequate handling of path traversal sequences, where the trailing dot character is not properly sanitized or interpreted by the server's file system access mechanisms. This flaw allows attackers to circumvent normal directory access restrictions that typically prevent direct access to application internals such as WEB-INF directories, which contain critical components including servlet class files, deployment descriptors, and application configuration data. The vulnerability operates at the application layer and demonstrates a classic path traversal attack pattern that has been documented in various security frameworks and threat models.
The operational impact of this vulnerability is severe as it provides attackers with access to sensitive application components that could reveal implementation details, configuration parameters, and potentially sensitive data. The WEB-INF directory typically contains critical application configuration files such as web.xml deployment descriptors, which may expose database connection strings, application logic, or other sensitive information that could be leveraged for further attacks. Additionally, access to Java class files could enable attackers to perform reverse engineering of application logic, potentially uncovering additional vulnerabilities or attack vectors that could be exploited in subsequent phases of an attack.
This vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, and represents a form of directory traversal that has been consistently identified in web server implementations across various platforms and technologies. The attack pattern corresponds to techniques documented in the MITRE ATT&CK framework under the T1083 discovery tactic, where adversaries seek to enumerate files and directories to understand system structure and identify potential targets for further exploitation. Organizations should implement proper input validation and path sanitization measures to prevent such traversal attacks, including implementing strict access controls for sensitive directories and ensuring that web server configurations properly restrict access to internal application components.
The remediation approach for this vulnerability involves implementing proper input validation and sanitization of all user-supplied paths before they are processed by the web server's file system access mechanisms. Security measures should include configuring the web server to reject or properly handle requests containing special path characters such as trailing dots, dots, or other directory traversal sequences. Additionally, proper access controls should be implemented to ensure that sensitive directories like WEB-INF remain protected from direct web access, with appropriate authentication and authorization mechanisms in place to prevent unauthorized access to application internals. Organizations should also consider implementing web application firewalls and security monitoring solutions to detect and prevent such traversal attempts in real-time.