CVE-2002-1861 in Easerver
Summary
by MITRE
Sybase Enterprise Application Server 4.0, 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 described in CVE-2002-1861 represents a critical directory traversal flaw within Sybase Enterprise Application Server version 4.0 running on Windows platforms. This security weakness stems from improper input validation in the web server's handling of file requests, specifically when processing directory paths that contain trailing dots. The issue allows remote attackers to bypass normal access controls and retrieve sensitive files from the WEB-INF directory, which typically contains critical application components including Java class files and configuration information that should remain protected from unauthorized access.
The technical implementation of this vulnerability exploits a fundamental flaw in how the application server processes file system requests. When a malicious user submits a request containing a path that ends with a trailing dot such as "WEB-INF.", the server fails to properly sanitize this input and instead treats it as a legitimate directory reference. This misconfiguration enables attackers to traverse the file system hierarchy and access files that should be restricted to authorized users only. The vulnerability specifically targets the WEB-INF directory structure which is a standard Java web application component designed to store server-side resources that should never be directly accessible to external clients.
The operational impact of this vulnerability extends beyond simple information disclosure, as the WEB-INF directory typically contains sensitive configuration files and compiled Java class files that could reveal application architecture, database connection strings, authentication mechanisms, and other critical system information. Attackers could potentially leverage this access to gain deeper insights into the application's internal workings, identify additional vulnerabilities, or even escalate their attack to compromise the entire application server. The remote nature of this exploit means that attackers do not require local system access or physical presence, making it particularly dangerous as it can be exploited from anywhere on the network.
This vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as directory traversal or path traversal attacks. The flaw demonstrates poor input validation practices that violate fundamental security principles of least privilege and proper access control enforcement. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1213.002 for Data from Information Repositories, as attackers can extract sensitive configuration data and application artifacts that would normally be protected within the application's secure boundaries. The security implications are compounded by the fact that this was a server-side vulnerability that could be exploited without requiring user interaction or specialized tools beyond basic web request manipulation.
Mitigation strategies for this vulnerability should include immediate patching of the Sybase Enterprise Application Server to the latest security updates provided by the vendor. Organizations should also implement proper input validation at all levels of the application stack, particularly when processing user-supplied paths or file references. Network-level protections such as web application firewalls and proper network segmentation can help limit the exposure of vulnerable systems. Additionally, security teams should conduct comprehensive audits of all web application components to identify similar path traversal vulnerabilities and ensure that directory access controls are properly enforced. Regular security assessments and penetration testing should be performed to validate that such vulnerabilities have been properly addressed and that the application maintains appropriate security boundaries.