CVE-2001-0453 in Webweaver
Summary
by MITRE
Directory traversal vulnerability in BRS WebWeaver HTTP server allows remote attackers to read arbitrary files via a .. (dot dot) attack in the (1) syshelp, (2) sysimages, or (3) scripts directories.
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Analysis
by VulDB Data Team • 05/27/2019
The CVE-2001-0453 vulnerability represents a critical directory traversal flaw in the BRS WebWeaver HTTP server implementation that fundamentally compromises file system access controls. This vulnerability resides in the server's handling of user-supplied input within specific directory paths, particularly affecting the syshelp, sysimages, and scripts directories. The flaw enables remote attackers to manipulate path resolution mechanisms through crafted dot-dot-slash sequences, effectively bypassing intended access restrictions and gaining unauthorized access to system resources.
The technical exploitation of this vulnerability leverages the server's insufficient input validation and path normalization processes. When the web server processes requests containing .. sequences within the specified directories, it fails to properly sanitize or validate the input before resolving file paths. This allows attackers to traverse upward through the directory structure and access files outside the intended web root or designated directories. The vulnerability specifically targets three critical system directories that typically contain sensitive configuration data, system help files, image resources, and executable scripts that should remain protected from unauthorized access.
From an operational impact perspective, this vulnerability presents a severe security risk that can lead to complete system compromise. Attackers can potentially access sensitive system files, configuration parameters, and user data that should remain isolated from public access. The vulnerability enables unauthorized information disclosure, which can result in exposure of system internals, authentication credentials, and potentially lead to further exploitation through the discovery of additional vulnerabilities. The remote nature of the attack means that adversaries can exploit this flaw from any location without requiring physical access or local system privileges.
The vulnerability aligns with CWE-22, which categorizes directory traversal attacks as a fundamental weakness in input validation and path handling. This weakness specifically manifests in the improper restriction of pathname characters or sequences, allowing attackers to access files outside the intended directory scope. The attack pattern corresponds to the MITRE ATT&CK framework's technique T1083, which covers directory and file discovery activities. Organizations running affected BRS WebWeaver servers face significant risk of data breaches and system compromise when this vulnerability remains unpatched, particularly in environments where sensitive information is stored within the affected directories.
Effective mitigation strategies include immediate application of vendor patches or updates that properly validate and sanitize all user-supplied input before path resolution. System administrators should implement input validation at multiple layers, including web server configuration, application-level validation, and network-level filtering. Additional protective measures include restricting file system permissions for the affected directories, implementing proper access controls, and conducting regular security assessments of web applications. Network segmentation and intrusion detection systems can help monitor for exploitation attempts, while regular security audits should verify that all directory traversal vulnerabilities have been addressed and that proper input validation mechanisms are in place to prevent similar issues in other components of the system infrastructure.