CVE-2017-16212 in ltt
Summary
by MITRE
ltt is a static file server. ltt is vulnerable to a directory traversal issue, giving an attacker access to the filesystem by placing "../" in the url.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 02/16/2020
The vulnerability identified as CVE-2017-16212 affects ltt, a static file server application that serves files from a web interface. This directory traversal vulnerability represents a critical security flaw that allows unauthorized access to the underlying filesystem through carefully crafted URL requests. The issue stems from insufficient input validation and sanitization within the application's path handling mechanism, specifically failing to properly sanitize user-supplied input that contains directory traversal sequences.
The technical flaw manifests when an attacker constructs malicious URLs containing "../" sequences that manipulate the file path resolution logic. This allows the application to traverse directories beyond its intended serving scope, potentially accessing sensitive system files, configuration data, or other restricted resources. The 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. This weakness enables attackers to access files and directories that are outside the intended scope of the web application, effectively bypassing access controls.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can lead to complete system compromise when combined with other attack vectors. An attacker could potentially access system configuration files, user credentials, application source code, or even execute arbitrary commands if the server has insufficient permissions. The vulnerability affects the principle of least privilege by allowing unauthorized access to resources that should remain protected. From an attack perspective, this represents a low-effort, high-impact exploit that requires minimal technical skill to execute, making it particularly dangerous in environments where ltt is deployed without proper network segmentation or additional security controls.
Mitigation strategies for CVE-2017-16212 should focus on implementing robust input validation and sanitization mechanisms to prevent directory traversal attempts. Organizations should immediately patch or upgrade to versions of ltt that address this vulnerability, as the fix typically involves implementing proper path normalization and validation routines. Network-level controls such as web application firewalls can provide additional protection by blocking suspicious URL patterns containing directory traversal sequences. The implementation of principle of least privilege should be enforced by restricting the web server's file system permissions, ensuring that the application can only access its intended serving directories. Additionally, regular security auditing and penetration testing should be conducted to identify similar vulnerabilities in other applications and services within the infrastructure, aligning with ATT&CK technique T1083 for discovering system information and T1213 for data from information repositories.