CVE-2017-16120 in liyujing
Summary
by MITRE
liyujing is a static file server. liyujing is vulnerable to a directory traversal issue, giving an attacker access to the filesystem by placing "../" in the url.
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Analysis
by VulDB Data Team • 02/16/2020
The CVE-2017-16120 vulnerability affects liyujing, a static file server implementation that suffers from a critical directory traversal flaw. This vulnerability enables remote attackers to access arbitrary files on the server's filesystem by manipulating URL parameters with ../ sequences. The issue stems from inadequate input validation and path sanitization within the server's file handling logic, allowing malicious users to navigate beyond the intended document root directory.
This directory traversal vulnerability represents a fundamental security flaw that directly violates the principle of least privilege and proper access control. The vulnerability falls under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw allows attackers to bypass normal file access controls and potentially gain access to sensitive system files, configuration data, or user information that should remain protected within the server's designated directories.
The operational impact of this vulnerability is significant as it provides attackers with unrestricted access to the underlying filesystem. An attacker can exploit this weakness to read system files, access sensitive configuration data, or potentially escalate privileges depending on the server's execution context. The vulnerability is particularly dangerous in environments where the static file server is used to serve content that includes sensitive information or where the server process runs with elevated privileges. This type of attack can lead to complete system compromise and data exfiltration.
Mitigation strategies for CVE-2017-16120 should focus on implementing proper input validation and sanitization mechanisms within the liyujing server implementation. The solution requires strict validation of all incoming file paths to prevent directory traversal sequences from being processed. Organizations should ensure that all user-supplied input is properly escaped and normalized before being used in file system operations. Additionally, implementing proper access controls and running the server with minimal required privileges can significantly reduce the potential impact of such vulnerabilities. This aligns with ATT&CK technique T1059 which covers command and scripting interpreters, and T1078 which addresses valid accounts and legitimate credentials, as the vulnerability essentially allows unauthorized access to system resources through malformed path requests.