CVE-2016-3956 in mpm
Summary
by MITRE
The CLI in npm before 2.15.1 and 3.x before 3.8.3, as used in Node.js 0.10 before 0.10.44, 0.12 before 0.12.13, 4 before 4.4.2, and 5 before 5.10.0, includes bearer tokens with arbitrary requests, which allows remote HTTP servers to obtain sensitive information by reading Authorization headers.
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Analysis
by VulDB Data Team • 08/26/2022
The vulnerability identified as CVE-2016-3956 represents a critical security flaw in the node package manager npm that affected multiple versions of the Node.js runtime environment. This issue stems from improper handling of authentication tokens within npm's command line interface, creating a significant risk for developers and system administrators who rely on npm for package management. The vulnerability specifically impacts npm versions prior to 2.15.1 and 3.x versions prior to 3.8.3, with corresponding Node.js versions including 0.10 before 0.10.44, 0.12 before 0.12.13, 4 before 4.4.2, and 5 before 5.10.0, making it a widespread concern across various Node.js releases.
The technical flaw manifests when npm's command line interface includes bearer tokens with arbitrary HTTP requests, allowing remote HTTP servers to access sensitive information through Authorization headers. This occurs because the npm client fails to properly sanitize or validate the authentication context when making requests to external servers, particularly when these requests are made to untrusted or malicious endpoints. The vulnerability essentially enables a man-in-the-middle attack scenario where unauthorized servers can intercept and extract authentication credentials, potentially compromising user accounts, private repositories, and sensitive project data. The flaw is categorized under CWE-200, which deals with exposure of sensitive information to an unauthorized actor, and aligns with ATT&CK technique T1552.001 for unsecured credentials.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can lead to complete account compromise and unauthorized access to private npm packages and repositories. Attackers can exploit this weakness to gain access to private packages, steal authentication tokens, and potentially execute malicious code through compromised package installations. The vulnerability is particularly dangerous in enterprise environments where developers frequently work with private package registries and sensitive corporate code. Additionally, the widespread adoption of npm across the Node.js ecosystem means that numerous applications and development workflows could be affected, creating a cascading security risk that extends far beyond individual applications. Organizations using npm for dependency management must consider the potential for credential theft and unauthorized package modifications when assessing their security posture.
Mitigation strategies for CVE-2016-3956 primarily focus on immediate version upgrades to patched releases of npm and Node.js. System administrators should prioritize updating their npm installations to versions 2.15.1 or later, or 3.x versions 3.8.3 and higher, while ensuring corresponding Node.js versions are also updated to prevent exploitation. Organizations should implement automated patch management systems to ensure all development environments remain current with security updates. Additional protective measures include configuring npm to use secure registries, implementing proper network segmentation, and monitoring for unauthorized access attempts. Security teams should also consider implementing credential rotation procedures and regularly auditing npm configuration settings to prevent similar vulnerabilities from arising in the future. The vulnerability demonstrates the critical importance of maintaining up-to-date package management tools and highlights the need for proper authentication handling in client-side applications that interact with external services.