CVE-2000-0540 in JRun
Summary
by MITRE
JSP sample files in Allaire JRun 2.3.x allow remote attackers to access arbitrary files (e.g. via viewsource.jsp) or obtain configuration information.
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Analysis
by VulDB Data Team • 10/14/2025
The vulnerability identified as CVE-2000-0540 represents a critical information disclosure flaw within Allaire JRun 2.3.x web application server software. This vulnerability specifically affects the Java Server Pages implementation and manifests through the presence of sample JSP files that contain insecure file access mechanisms. The flaw allows remote attackers to exploit weaknesses in the server's file handling capabilities, potentially enabling unauthorized access to sensitive system resources and configuration data. The vulnerability is particularly concerning because it affects the default installation of the software, making it readily exploitable by threat actors without requiring specialized knowledge or privileged access.
The technical implementation of this vulnerability stems from the insecure design of sample JSP files included with JRun 2.3.x, particularly the viewsource.jsp component. These files fail to properly validate or sanitize user input parameters that control file access operations, creating a path traversal condition that enables attackers to specify arbitrary file paths. The flaw operates at the application layer and leverages the server's inability to properly restrict access to system files, configuration directories, or other sensitive resources. This type of vulnerability is classified under CWE-22 as Path Traversal, where insufficient input validation allows attackers to access files outside the intended directory structure. The vulnerability demonstrates poor input sanitization practices and inadequate access controls within the application's file handling mechanisms.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. An attacker who successfully exploits this vulnerability can gain access to sensitive configuration files that may contain database connection strings, administrative credentials, or other system-specific information. This information can then be used to conduct further attacks, escalate privileges, or gain deeper access to the underlying system. The vulnerability affects the confidentiality and integrity of the system, as unauthorized parties can access potentially sensitive data that should remain protected. The attack vector is particularly dangerous because it requires no authentication and can be executed remotely, making it an attractive target for automated exploitation tools. According to ATT&CK framework, this vulnerability maps to T1213 (Data from Information Repositories) and T1566 (Phishing with Malicious Attachments) as attackers can use the disclosed information to craft more targeted attacks.
The mitigation strategies for this vulnerability involve multiple layers of defensive measures. The primary recommendation is to immediately patch or upgrade to a version of JRun that addresses this flaw, as Allaire released updated versions that properly implement input validation and access controls. Organizations should also implement proper network segmentation and firewall rules to restrict access to application servers, particularly those running older versions of JRun. Additionally, administrators should remove or secure the sample JSP files that contain vulnerable code, ensuring that only necessary application files remain accessible. Configuration management practices should include regular audits of installed files and removal of default installations that contain known vulnerabilities. The vulnerability also highlights the importance of secure coding practices and proper input validation, as outlined in industry standards such as the OWASP Top Ten and NIST Cybersecurity Framework, which emphasize the need for robust access controls and secure file handling mechanisms in web applications.