CVE-2001-1544 in JRun
Summary
by MITRE
Directory traversal vulnerability in Macromedia JRun Web Server (JWS) 2.3.3, 3.0 and 3.1 allows remote attackers to read arbitrary files via a .. (dot dot) in the HTTP GET request.
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Analysis
by VulDB Data Team • 09/24/2025
The vulnerability identified as CVE-2001-1544 represents a critical directory traversal flaw within Macromedia JRun Web Server versions 2.3.3, 3.0, and 3.1. This security weakness stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data in HTTP GET requests. The vulnerability specifically manifests when the web server processes URL paths containing double dot sequences, which are commonly used to navigate up directory levels in file systems. Attackers can exploit this flaw by crafting malicious HTTP requests that include .. (dot dot) sequences in the requested resource paths, thereby gaining unauthorized access to files outside the intended web root directory. The underlying technical root cause aligns with CWE-22, which categorizes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal vulnerabilities. This weakness allows attackers to bypass normal access controls and potentially access sensitive system files, configuration data, or other restricted resources that should remain protected from external access.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to access arbitrary files on the affected system. In the context of web application security, this vulnerability enables attackers to potentially retrieve sensitive configuration files, database connection strings, application source code, or other confidential data that could be used for further exploitation. The vulnerability's remote nature means that attackers do not require local system access or credentials to exploit it, making it particularly dangerous in internet-facing web applications. The affected versions of JRun Web Server were widely deployed in enterprise environments, amplifying the potential impact of this vulnerability across multiple organizations. From an attacker's perspective, this flaw aligns with techniques described in the ATT&CK framework under the T1083 discovery tactic, where adversaries attempt to gather information about the target system's file structure and available resources. The vulnerability also relates to T1566, which covers initial access through malicious web content, as attackers could leverage this weakness to gain access to sensitive files and potentially escalate privileges.
Mitigation strategies for CVE-2001-1544 require immediate implementation of input validation and sanitization measures within the affected web server configuration. Organizations should implement proper path normalization and validation techniques that prevent double dot sequences from being processed in file path requests. The recommended approach involves filtering or rejecting any HTTP GET requests containing .. (dot dot) sequences in the requested resource paths. Additionally, system administrators should ensure that the web server operates with minimal privileges and that access controls are properly configured to limit file system access. The implementation of web application firewalls or intrusion prevention systems can provide additional layers of protection by detecting and blocking malicious path traversal attempts. Organizations should also consider implementing proper logging and monitoring of file access patterns to detect potential exploitation attempts. The vulnerability highlights the importance of secure coding practices and input validation as emphasized in industry standards such as the OWASP Top Ten and NIST cybersecurity guidelines. Regular security assessments and patch management processes should be implemented to prevent similar vulnerabilities from being introduced in future deployments. Organizations using legacy JRun Web Server versions should plan for immediate migration to supported, secure web server solutions, as these older versions are no longer receiving security updates or support from the vendor.