CVE-2017-16133 in goserv
Summary
by MITRE
goserv is an http server. goserv 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 vulnerability identified as CVE-2017-16133 affects goserv, an http server implementation that suffers from a critical directory traversal flaw. This weakness allows remote attackers to access arbitrary files on the server's filesystem by manipulating URL paths through the strategic insertion of "../" sequences. The issue stems from insufficient input validation and path sanitization within the server's request handling mechanism, creating an avenue for unauthorized file system access that can potentially expose sensitive data, configuration files, or system resources to malicious actors.
This directory traversal vulnerability represents a classic security flaw that falls under the Common Weakness Enumeration category CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory. The flaw enables attackers to bypass normal access controls and navigate through the file system hierarchy by exploiting the server's failure to properly validate or sanitize user-supplied input. When goserv processes requests containing directory traversal sequences, it fails to adequately restrict file access to the intended web root directory, allowing attackers to ascend directory levels and access files outside of the designated serving scope.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can potentially enable attackers to access critical system files, configuration data, application source code, or even execute arbitrary commands if the server is running with elevated privileges. An attacker could leverage this weakness to obtain database credentials, application secrets, system configuration files, or other sensitive information that could lead to further compromise of the affected system. The vulnerability is particularly concerning in environments where goserv is used to serve web content, as it could expose the entire file system hierarchy to unauthorized access.
Mitigation strategies for CVE-2017-16133 should focus on implementing proper input validation and path sanitization within the goserv application. The most effective approach involves ensuring that all user-supplied paths are properly validated against a whitelist of acceptable directories or that all path traversal sequences are explicitly rejected during request processing. Organizations should also consider implementing web application firewalls that can detect and block suspicious path traversal patterns, as well as regularly updating and patching the goserv software to address known vulnerabilities. Additionally, following the principle of least privilege by running the server with minimal required permissions can limit the potential damage from successful exploitation attempts. Security practitioners should also monitor network traffic for suspicious URL patterns that may indicate attempts to exploit this vulnerability, as outlined in the attack techniques documented within the MITRE ATT&CK framework under the category of credential access and reconnaissance activities.