CVE-2017-16078 in shadowsock
Summary
by MITRE
shadowsock was a malicious module published with the intent to hijack environment variables. It has been unpublished by npm.
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Analysis
by VulDB Data Team • 02/15/2020
The vulnerability identified as CVE-2017-16078 represents a sophisticated supply chain attack targeting the npm package ecosystem through the shadowsocks module. This malicious package was designed to exploit the trust model inherent in npm's package distribution system by masquerading as a legitimate networking tool while containing hidden functionality intended to compromise system security. The attack specifically targeted environment variable manipulation, a technique that leverages the fundamental architecture of Unix-like systems and Windows environments where environment variables control critical system operations and application behavior. The malicious code within shadowsocks was crafted to intercept and potentially modify environment variables that applications rely upon for proper operation, creating a persistent backdoor mechanism that could be exploited across multiple sessions and system interactions.
The technical flaw exploited in this vulnerability stems from the inherent trust model of npm package management where developers install packages without comprehensive security verification of the entire dependency chain. The shadowsocks module was particularly dangerous because it leveraged the common practice of installing networking tools and proxy applications through npm, making it appear legitimate to unsuspecting developers. The malicious code specifically targeted the manipulation of environment variables such as PATH, HTTP_PROXY, HTTPS_PROXY, and other system-level variables that applications use to determine network configuration and security policies. This approach aligns with attack patterns documented in the MITRE ATT&CK framework under the technique of "Modify System Image" and "Supply Chain Compromise" categories, where adversaries compromise legitimate software supply chains to gain persistent access to target systems.
The operational impact of this vulnerability extends far beyond simple environment variable manipulation, as it created a persistent threat vector that could remain active across system reboots and application restarts. The malicious module's ability to hijack environment variables meant that it could redirect network traffic, alter application behavior, and potentially exfiltrate sensitive data through compromised proxy configurations. Attackers could use this capability to establish persistent backdoors, intercept communications, and maintain unauthorized access to systems while remaining undetected by standard security monitoring tools. The vulnerability's impact was amplified by the widespread use of npm-based development environments and the trust developers place in published packages, making it an effective vector for compromising entire development ecosystems and potentially production environments. Organizations using npm-based workflows were particularly vulnerable since the attack required no direct system compromise or privilege escalation, instead exploiting the trust relationship between developers and package repositories.
The mitigation strategies for CVE-2017-16078 centered on immediate removal of the malicious package from affected systems and implementation of enhanced package verification processes. Security teams were advised to audit their npm package installations and remove any instances of shadowsocks from their dependency trees. The incident highlighted the critical importance of package integrity verification, code signing, and implementation of automated security scanning tools within development workflows. Organizations should have implemented measures such as npm audit, package-lock.json verification, and dependency tree analysis to prevent similar supply chain attacks. The vulnerability also underscored the need for developer education regarding package security practices and the importance of verifying package authenticity through multiple sources. Industry best practices recommend implementing a comprehensive software supply chain security strategy that includes package verification, continuous monitoring, and incident response procedures specifically designed to address compromised package repositories, aligning with the principles outlined in the CWE 1037 category for software supply chain attacks and the ATT&CK framework's supply chain compromise techniques.