CVE-2017-1000209 in nv-websocket-client
Summary
by MITRE
The Java WebSocket client nv-websocket-client does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL/TLS servers via an arbitrary valid certificate.
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Analysis
by VulDB Data Team • 01/10/2023
The vulnerability identified as CVE-2017-1000209 affects the nv-websocket-client Java library, which is widely used for implementing WebSocket client functionality in Java applications. This security flaw represents a critical certificate validation weakness that undermines the fundamental security guarantees of SSL/TLS communications. The vulnerability stems from improper implementation of hostname verification during the SSL/TLS handshake process, creating a significant attack surface for malicious actors seeking to compromise secure WebSocket connections. The affected library fails to perform the essential validation step that ensures the server certificate's hostname matches the expected domain name, thereby allowing attackers to establish fraudulent secure connections.
The technical root cause of this vulnerability lies in the library's deviation from standard SSL/TLS certificate validation procedures. According to industry standards such as RFC 2818 and RFC 6125, secure communication requires that the hostname used to establish a connection must match either the Common Name field or the Subject Alternative Name fields within the X.509 certificate. The nv-websocket-client library bypasses this critical validation step, allowing man-in-the-middle attackers to present any valid certificate and successfully establish a secure-looking connection to the client. This flaw directly maps to CWE-295, which specifically addresses "Improper Certificate Validation" and represents a well-documented weakness in cryptographic implementations. The vulnerability creates a scenario where attackers can intercept, modify, or redirect WebSocket traffic without detection.
The operational impact of this vulnerability extends far beyond simple network monitoring, as WebSocket connections are commonly used for real-time communication in enterprise applications, financial systems, and web-based platforms. Attackers exploiting this vulnerability can conduct sophisticated man-in-the-middle attacks that allow them to eavesdrop on sensitive communications, inject malicious data, or redirect users to malicious endpoints. The implications are particularly severe in environments where WebSocket connections carry authentication tokens, personal data, financial information, or proprietary business communications. This vulnerability essentially allows attackers to establish trust relationships with legitimate clients while operating as malicious intermediaries, creating a persistent threat vector that can remain undetected for extended periods. The attack surface is broad since the library is used across various Java applications, making numerous systems potentially vulnerable to this specific class of attack.
Mitigation strategies for this vulnerability require immediate attention from system administrators and developers who utilize the affected library. The primary solution involves upgrading to a patched version of the nv-websocket-client library that properly implements hostname verification according to industry standards. Organizations should also implement additional network-level security controls such as certificate pinning, which provides an extra layer of protection by explicitly defining which certificates or certificate authorities are trusted. Network monitoring solutions should be enhanced to detect anomalous WebSocket traffic patterns that might indicate man-in-the-middle activity. Security teams should conduct comprehensive vulnerability assessments to identify all systems using the affected library and ensure proper patch management procedures are in place. Additionally, implementing proper certificate management practices and regular security audits can help prevent similar issues from arising in other components of the application infrastructure. The vulnerability highlights the critical importance of adhering to established cryptographic security practices and demonstrates how seemingly minor implementation flaws can create significant security risks in modern networked applications.