CVE-2017-9031 in Deluge
Summary
by MITRE
The WebUI component in Deluge before 1.3.15 contains a directory traversal vulnerability involving a request in which the name of the render file is not associated with any template file.
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Analysis
by VulDB Data Team • 12/06/2022
The vulnerability identified as CVE-2017-9031 resides within the WebUI component of the Deluge BitTorrent client software, affecting versions prior to 1.3.15. This directory traversal flaw represents a critical security weakness that allows unauthorized access to arbitrary files on the system where the Deluge service is running. The vulnerability specifically manifests when processing requests that involve rendering files without proper validation of the template file names, creating an opportunity for malicious actors to exploit the system's file access mechanisms. The issue stems from insufficient input sanitization and validation within the WebUI's template rendering engine, which fails to properly verify or restrict the paths specified in file name parameters.
The technical exploitation of this vulnerability occurs through carefully crafted HTTP requests that manipulate the file path parameters used in the template rendering process. When a user submits a request containing a malicious file path, the WebUI component processes this input without adequate sanitization, potentially allowing access to sensitive files such as configuration files, user credentials, or system files that should remain protected. This type of vulnerability falls under the Common Weakness Enumeration category CWE-22, which specifically addresses Improper Limitation of a Pathname to a Restricted Directory, commonly known as directory traversal or path traversal attacks. The vulnerability enables an attacker to bypass normal access controls and retrieve files from locations outside the intended web root directory, potentially leading to complete system compromise.
The operational impact of CVE-2017-9031 extends beyond simple information disclosure, as it can facilitate further exploitation attempts within the compromised environment. An attacker who successfully exploits this vulnerability gains the ability to read arbitrary files on the system, which may include database files containing user information, configuration files with sensitive settings, or even system files that could reveal network architecture details. This reconnaissance capability allows for more sophisticated attacks, including privilege escalation attempts or the extraction of credentials that could be used to access other systems within the network. The vulnerability is particularly concerning in environments where Deluge is running with elevated privileges or where it has access to sensitive data repositories, as it could provide a foothold for lateral movement and persistent access.
Mitigation strategies for this vulnerability primarily focus on upgrading to Deluge version 1.3.15 or later, which includes proper input validation and sanitization measures for template file paths. System administrators should also implement network segmentation and access controls to limit exposure of the Deluge WebUI to untrusted networks. Additional protective measures include restricting file system permissions for the Deluge service account, implementing web application firewalls to monitor and filter suspicious requests, and conducting regular security assessments to identify similar vulnerabilities in other components. Organizations should also consider implementing monitoring solutions that can detect anomalous file access patterns or attempts to exploit directory traversal vulnerabilities. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege in web application security, aligning with ATT&CK technique T1083 for discovering system information and T1078 for valid accounts, as exploitation often requires understanding of the target system's file structure and access controls.