CVE-2022-31552 in corpus
Summary
by MITRE • 07/11/2022
The project-anuvaad/anuvaad-corpus repository through 2020-11-23 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-2022-31552 resides within the project-anuvaad/anuvaad-corpus repository, a software project designed for corpus processing and natural language understanding tasks. This repository, which was last updated on November 23, 2020, contains a critical security flaw that stems from improper implementation of file serving functionality. The issue manifests when the Flask web framework's send_file function is invoked without adequate input validation, creating an exploitable condition that allows attackers to access arbitrary files on the server's filesystem.
The technical root cause of this vulnerability aligns with CWE-22, known as "Improper Limitation of a Pathname to a Restricted Directory." The Flask send_file function, when used without proper sanitization of user-provided input, enables attackers to manipulate file paths and traverse the filesystem beyond intended boundaries. This occurs because the application fails to validate or sanitize the file paths provided by users, allowing malicious actors to craft requests that include absolute paths or directory traversal sequences such as ../ or ..\ that can bypass normal file access controls.
The operational impact of this vulnerability is significant and multifaceted. An attacker who successfully exploits this flaw can potentially access sensitive files including configuration data, database credentials, source code, and other confidential information stored on the server. This represents a critical compromise of data confidentiality and system integrity, as the vulnerability allows for arbitrary file reading capabilities that could lead to complete system compromise. The threat landscape for this vulnerability aligns with ATT&CK technique T1083, which covers "File and Directory Discovery" and T1566, covering "Phishing with Malicious Attachment" where the compromised system could serve as a staging point for further attacks.
The exploitation of this vulnerability typically occurs through web requests that manipulate parameters controlling file paths. Attackers can construct malicious URLs that include absolute paths or directory traversal sequences, causing the Flask application to serve files from unintended locations on the filesystem. This vulnerability is particularly dangerous because it can be exploited without authentication, making it an attractive target for automated scanning and exploitation tools. The impact extends beyond simple data theft to include potential system compromise through access to system configuration files, log files, and other sensitive artifacts that could reveal additional attack vectors or system weaknesses.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and sanitization of all file path parameters. The recommended approach involves using Flask's built-in security features such as the use of safe file path resolution, implementing proper file access controls, and validating all user-provided paths against a whitelist of allowed directories. Additionally, organizations should consider implementing proper access controls, using secure coding practices that prevent path traversal attacks, and regularly updating their software dependencies to address known vulnerabilities. The implementation of principle of least privilege access controls and regular security audits can significantly reduce the risk of exploitation. Organizations should also consider implementing web application firewalls and monitoring systems to detect and prevent suspicious file access patterns that could indicate exploitation attempts.