CVE-2022-31572 in cockybook
Summary
by MITRE • 07/11/2022
The ceee-vip/cockybook repository through 2015-04-16 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-2022-31572 resides within the ceee-vip/cockybook repository, which was last updated on April 16, 2015, and represents a critical path traversal flaw that directly impacts web application security. This issue manifests through the unsafe usage of Flask's send_file function, which is a core component of the Python web framework used for serving files to clients. The repository's implementation fails to properly validate or sanitize file paths provided by users, creating an exploitable condition where malicious actors can access arbitrary files on the server's filesystem. Such vulnerabilities fall under the category of CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which is a well-documented weakness in software security that directly enables unauthorized access to sensitive data. The vulnerability represents a fundamental flaw in input validation and access control mechanisms, as the Flask application does not properly restrict the paths that can be accessed through the file serving functionality.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious request that includes an absolute path traversal payload, typically involving sequences such as ../../ or similar directory traversal patterns. When the Flask application processes this request through the send_file function without proper sanitization, the function interprets the malicious path and attempts to serve the file from the specified location on the server. This allows attackers to bypass normal access controls and potentially retrieve sensitive files including configuration files, database credentials, source code, or other confidential information stored on the server. The vulnerability is particularly dangerous because it operates at the filesystem level, meaning that an attacker could potentially access any file that the web application process has read permissions for, including system files, application secrets, or user data. This represents a direct violation of the principle of least privilege and demonstrates poor security architecture design.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can serve as a stepping stone for more sophisticated attacks within the target environment. An attacker who successfully exploits this vulnerability can gain access to sensitive information that may include database connection strings, API keys, cryptographic certificates, or application configuration files that could be used for further exploitation. The vulnerability also demonstrates poor security practices in the development lifecycle, as it suggests that proper input validation and security testing were not implemented during the development process. This weakness aligns with ATT&CK technique T1213 - Data from Information Repositories, where adversaries attempt to access and exfiltrate data from repositories such as web applications. Additionally, the vulnerability could enable privilege escalation attacks if the web application process runs with elevated permissions, potentially allowing attackers to access system-level files or execute commands on the server. The long timeframe between the vulnerability's introduction and its discovery indicates that the application may have been operating without proper security monitoring or regular vulnerability assessments.
Mitigation strategies for CVE-2022-31572 must address both the immediate security issue and improve overall application security posture. The primary fix involves implementing proper input validation and sanitization of file paths before passing them to the Flask send_file function, ensuring that all paths are resolved relative to a predetermined safe directory and that absolute paths are rejected. Developers should implement a whitelist approach for file access, allowing only specific directories or file types to be served, and should avoid using user-supplied input directly in file path construction. The application should also implement proper access controls and authentication mechanisms to prevent unauthorized access to file serving endpoints. Organizations should conduct regular security assessments and vulnerability scans to identify similar issues in other applications, as this vulnerability type is commonly found in web applications that do not properly validate user input. Additionally, implementing proper logging and monitoring of file access patterns can help detect and respond to potential exploitation attempts. The fix should also include updating the application to use more secure file serving methods and ensuring that the web application operates with minimal required privileges to reduce the potential impact of successful exploitation. This vulnerability serves as a reminder of the critical importance of secure coding practices and the need for comprehensive security testing throughout the software development lifecycle, particularly for web applications that handle file operations.