CVE-2022-31544 in rbtm
Summary
by MITRE • 07/11/2022
The meerstein/rbtm repository through 1.5 on GitHub allows absolute path traversal because the Flask send_file function is used unsafely.
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Analysis
by VulDB Data Team • 07/21/2022
The vulnerability identified as CVE-2022-31544 resides within the meerstein/rbtm repository version 1.5 and earlier, presenting a critical security flaw that enables unauthorized access to arbitrary files on the server. This repository appears to be a web application built using the Flask framework, which is commonly employed for developing web services and applications. The core issue stems from improper handling of file paths within the application's file serving functionality, creating a pathway for attackers to access sensitive files beyond the intended directory structure.
The technical implementation flaw occurs when the Flask send_file function is invoked without proper validation of the file path parameter. This function is designed to serve files from the server to clients, but when used unsafely, it fails to sanitize user input that determines which file to serve. Attackers can manipulate input parameters to include directory traversal sequences such as ../ or ..\ that allow them to navigate outside the intended document root or designated file serving directory. This vulnerability directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks.
The operational impact of this vulnerability is severe and multifaceted, potentially exposing sensitive system information, configuration files, source code, and other confidential data to unauthorized parties. An attacker could leverage this weakness to access database connection strings, API keys, administrative credentials, and other critical system artifacts stored in files accessible through the web application. The implications extend beyond simple data theft, as this vulnerability could enable further exploitation leading to complete system compromise. According to ATT&CK framework, this vulnerability aligns with T1083 (File and Directory Discovery) and T1566 (Phishing with Malicious Attachments) techniques, as it provides attackers with access to files that could be used for privilege escalation or additional attack vectors.
Mitigation strategies for CVE-2022-31544 require immediate implementation of proper input validation and sanitization measures. The Flask application should employ absolute path resolution techniques that prevent any user-supplied input from traversing beyond the intended directory boundaries. Implementing a whitelist approach for file access, where only explicitly allowed files can be served, provides the most robust protection against such attacks. Additionally, developers should utilize Flask's built-in security mechanisms such as the send_from_directory function which properly handles path validation. Regular security audits and code reviews should focus on identifying all instances where file serving functions are used, ensuring that all user inputs are properly sanitized and validated before being processed. The repository maintainers should also implement proper access controls and authentication mechanisms to limit who can access potentially sensitive file serving endpoints, reducing the attack surface and potential impact of any remaining vulnerabilities.