CVE-2022-31536 in ytdl-sync
Summary
by MITRE • 07/11/2022
The jaygarza1982/ytdl-sync repository through 2021-01-02 on GitHub allows absolute path traversal because the Flask send_file function is used unsafely.
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Analysis
by VulDB Data Team • 07/20/2022
The vulnerability identified as CVE-2022-31536 resides within the jaygarza1982/ytdl-sync repository, a tool designed for synchronizing YouTube downloads. This repository, as of the 2021-01-02 release, contains a critical security flaw that stems from improper handling of file paths in a Flask web application. The vulnerability manifests when the Flask send_file function is invoked without adequate sanitization of user-provided input, creating an opportunity for attackers to access arbitrary files on the server filesystem. This particular flaw represents a direct violation of secure coding practices and demonstrates a dangerous lack of input validation that could enable unauthorized data access.
The technical implementation of this vulnerability occurs through the unsafe usage of Flask's send_file function, which is designed to serve files from the server to clients. When the application accepts user input that specifies file paths and directly passes this input to send_file without proper validation or sanitization, it creates a path traversal condition. Attackers can exploit this by crafting malicious requests that include directory traversal sequences such as ../ or ..\, allowing them to navigate beyond the intended directory boundaries and access files that should remain protected. This behavior aligns with CWE-22, which specifically addresses path traversal vulnerabilities in software systems. The flaw essentially allows an attacker to bypass normal access controls and retrieve sensitive files from the server's file system.
The operational impact of this vulnerability extends beyond simple data theft, as it provides attackers with the ability to access potentially sensitive information stored on the server. Depending on the server configuration and file permissions, an attacker might gain access to configuration files, database credentials, source code, or other confidential data. The implications are particularly severe for applications that run with elevated privileges or contain sensitive user information. This vulnerability can be leveraged as part of a broader attack strategy, potentially serving as a foothold for further exploitation or as a means to escalate privileges within the system. The attack vector is relatively straightforward, requiring only that an attacker identify the vulnerable endpoint and construct appropriate traversal sequences to access desired files.
Mitigation strategies for this vulnerability require immediate attention and implementation of proper input validation and sanitization measures. The primary fix involves ensuring that all user-provided path inputs are properly validated and sanitized before being passed to Flask's send_file function. This includes implementing strict path validation that verifies file paths are within the intended directory boundaries and rejects any input containing traversal sequences. Organizations should also consider implementing the principle of least privilege when running the application, limiting the file system access of the application to only necessary directories. Additionally, regular security audits and code reviews should be conducted to identify similar patterns that might exist elsewhere in the codebase. This vulnerability demonstrates the importance of following secure coding practices and adheres to ATT&CK technique T1213, which involves data from information repositories, as attackers can leverage such vulnerabilities to access sensitive data stored within application environments. The fix should include comprehensive testing to ensure that path traversal attempts are properly blocked while maintaining legitimate functionality of the application's file serving capabilities.