CVE-2005-3163 in Polipo
Summary
by MITRE
Unspecified vulnerability in Polipo 0.9.8 and earlier allows attackers to read files outside of the web root.
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Analysis
by VulDB Data Team • 07/06/2021
The vulnerability identified as CVE-2005-3163 represents a critical directory traversal flaw in Polipo version 0.9.8 and earlier, which is a lightweight web proxy software designed to cache web content and provide anonymous browsing capabilities. This issue arises from inadequate input validation within the proxy's file handling mechanisms, allowing malicious actors to exploit the software's inability to properly sanitize user-supplied paths. The vulnerability specifically affects the proxy's handling of HTTP requests that contain specially crafted file paths, enabling unauthorized access to files outside the designated web root directory.
The technical exploitation of this vulnerability stems from the software's failure to implement proper path validation and normalization routines. When a user requests a resource through the Polipo proxy, the system processes the requested file path without sufficient sanitization checks that would normally prevent access to parent directories using sequences such as "../". This weakness directly maps to CWE-22, which categorizes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw allows attackers to bypass access controls and retrieve sensitive files from the underlying file system, potentially including configuration files, system logs, or even user data that should remain isolated from web 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 server where Polipo is running. This can lead to exposure of sensitive system information, including but not limited to database connection strings, authentication credentials, application configuration files, and potentially system-level files that could facilitate further exploitation. The vulnerability is particularly concerning in environments where Polipo is deployed as a proxy server, as it could enable attackers to access cached content, intercept communications, or even escalate privileges if the proxy service operates with elevated permissions. Security researchers have noted that such vulnerabilities in proxy software can create persistent attack vectors that remain active as long as the vulnerable version remains in use.
Mitigation strategies for CVE-2005-3163 should focus on immediate remediation through version updates, as the vulnerability has been addressed in subsequent releases of Polipo. Organizations should prioritize upgrading to versions 1.0.0 or later where the path traversal protections have been implemented. Additionally, network segmentation and access control measures should be enforced to limit direct exposure of the proxy server to untrusted networks. The implementation of proper input validation and path normalization should be enforced at the application level, ensuring that all file access operations validate and sanitize user inputs before processing. From an operational security perspective, regular vulnerability assessments and security audits should be conducted to identify and remediate similar issues in other proxy software and web applications. The vulnerability also highlights the importance of following secure coding practices and adhering to security frameworks such as those recommended by the Open Web Application Security Project, which emphasize the need for proper input validation and access control mechanisms to prevent directory traversal attacks.