CVE-2002-1837 in Image Display System
Summary
by MITRE
The getAlbumToDisplay function in idsShared.pm for Image Display System (IDS) 0.81 allows remote attackers to determine the existence of arbitrary directories via ".." sequences in the album parameter, which generates different error messages depending on whether the directory exists or not.
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Analysis
by VulDB Data Team • 08/12/2024
The vulnerability described in CVE-2002-1837 affects the Image Display System IDS version 0.81 through a flaw in the getAlbumToDisplay function within the idsShared.pm module. This issue represents a directory traversal attack vector that enables remote adversaries to enumerate the existence of arbitrary directories on the target system by manipulating the album parameter with ".." sequences. The vulnerability stems from inadequate input validation and sanitization within the image display system's directory handling mechanism, creating a path traversal condition that exposes system file structure information through differential error responses.
The technical implementation of this vulnerability exploits the lack of proper parameter validation in the idsShared.pm script where the album parameter is directly processed without adequate sanitization. When attackers submit directory traversal sequences using ".." characters in the album parameter, the system processes these inputs and generates distinct error messages based on whether the specified directory path exists or not. This behavior creates a timing-based information disclosure mechanism where successful directory enumeration is possible through the variation in error responses, effectively allowing attackers to map the underlying file system structure without direct access to the system's file system.
From an operational impact perspective, this vulnerability provides attackers with significant reconnaissance capabilities that can lead to more severe exploitation opportunities. The ability to determine directory existence enables attackers to map the file system structure of the target server, potentially identifying sensitive directories, configuration files, or other system components that could be targeted in subsequent attacks. This information disclosure vulnerability can be leveraged as a reconnaissance primitive in broader attack campaigns and aligns with attack techniques categorized under the ATT&CK framework's reconnaissance phase, specifically targeting credential access and privilege escalation pathways.
The vulnerability demonstrates a classic lack of proper input validation and output sanitization that violates fundamental security principles outlined in CWE-22, which addresses directory traversal vulnerabilities. The system's failure to properly validate user-supplied input before processing it in a context that affects the file system creates an information disclosure vulnerability that can be exploited without authentication. Security practitioners should note that this vulnerability type is particularly dangerous because it requires minimal privileges and can be exploited through simple HTTP requests, making it an attractive target for automated scanning tools and opportunistic attackers.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and sanitization mechanisms within the IDS system. Organizations should ensure that all user-supplied parameters undergo rigorous validation before being processed, particularly when these parameters are used in file system operations. The recommended approach involves implementing strict parameter validation that rejects or normalizes directory traversal sequences, implementing proper access controls, and ensuring that error messages do not reveal system-specific information that could aid attackers in their reconnaissance efforts. Additionally, implementing a principle of least privilege for file system access and regular security auditing of web applications can help prevent similar vulnerabilities from being exploited in production environments.