CVE-2017-16183 in iter-server
Summary
by MITRE
iter-server is a static file server. iter-server 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-2017-16183 vulnerability affects iter-server, a static file server implementation that suffers from a critical directory traversal flaw. This vulnerability allows remote attackers to access arbitrary files on the server's filesystem by manipulating URL paths through the use of directory traversal sequences such as "../". The flaw represents a fundamental security weakness in how the server processes file requests and validates path inputs, creating an opportunity for unauthorized data access that can range from sensitive configuration files to system binaries and user data. This type of vulnerability is particularly dangerous because it can enable attackers to bypass normal access controls and potentially escalate their privileges within the affected system.
The technical root cause of this vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The vulnerability manifests when the server fails to properly sanitize or validate user-supplied input that contains directory traversal sequences. When a malicious user submits a URL containing "../" sequences, the server processes these requests without adequate validation, allowing the attacker to navigate up the directory hierarchy and access files outside the intended document root. This weakness can be exploited through various means including direct URL manipulation, web application attacks, or even through server-side request forgery techniques that leverage the vulnerable server as an attack vector.
The operational impact of CVE-2017-16183 extends beyond simple unauthorized file access, as it can enable attackers to extract sensitive information such as configuration files, database credentials, application source code, and other critical system artifacts. Depending on the server configuration and the files accessible through the traversal, attackers may be able to gain insights into the system architecture, discover additional vulnerabilities, or even extract authentication tokens and other security credentials. The vulnerability can be exploited through standard HTTP requests, making it relatively easy to detect and exploit without requiring specialized tools or techniques. This accessibility significantly increases the risk profile of affected systems and can lead to data breaches, system compromise, or further attack escalation.
Mitigation strategies for CVE-2017-16183 should focus on implementing proper input validation and sanitization mechanisms to prevent directory traversal attempts. Organizations should ensure that all user-supplied input is properly validated and that the server enforces strict path validation to prevent traversal sequences from being processed. The implementation of secure coding practices including the use of allowlists for valid file paths, proper directory restriction mechanisms, and input normalization techniques can effectively prevent this class of vulnerability. Additionally, deploying web application firewalls, implementing proper access controls, and regularly updating server software can provide additional layers of defense. According to ATT&CK framework, this vulnerability maps to T1083 (File and Directory Discovery) and T1071.004 (Application Layer Protocol: DNS) when used as part of reconnaissance activities, and T1566 (Phishing) when combined with social engineering to deliver malicious URLs to victims. Regular security assessments and penetration testing should be conducted to identify and remediate similar vulnerabilities across the organization's infrastructure.