CVE-2019-10746 in Communications Cloud Native Core Network Function Cloud Native Environment
Summary
by MITRE
mixin-deep is vulnerable to Prototype Pollution in versions before 1.3.2 and version 2.0.0. The function mixin-deep could be tricked into adding or modifying properties of Object.prototype using a constructor payload.
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Analysis
by VulDB Data Team • 07/23/2021
The vulnerability identified as CVE-2019-10746 affects the mixin-deep npm package, which is widely used for deep merging JavaScript objects. This issue represents a prototype pollution vulnerability that allows attackers to manipulate the Object.prototype object through malicious constructor payloads. The vulnerability exists in versions prior to 1.3.2 and specifically affects version 2.0.0 of the package, making it a persistent threat across multiple release lines. The flaw stems from inadequate input validation within the mixin-deep function that processes object merging operations.
The technical implementation of this vulnerability occurs when the mixin-deep function processes user-controlled input without proper sanitization of property names. Attackers can craft malicious payloads containing constructor properties such as constructor or prototype that, when processed by the vulnerable function, result in modifications to the Object.prototype object. This occurs because the function does not properly validate or sanitize property names during the merging process, allowing attackers to inject properties that persist across all objects derived from Object.prototype. The vulnerability is classified as CWE-471, which specifically addresses the issue of adding or modifying properties of objects with prototype pollution. This type of vulnerability is particularly dangerous because it affects the fundamental object model of JavaScript applications.
The operational impact of CVE-2019-10746 extends beyond simple property manipulation and can lead to severe security consequences including remote code execution, privilege escalation, and denial of service conditions. When Object.prototype is polluted, all JavaScript objects in the application inherit these malicious properties, potentially enabling attackers to bypass security controls, manipulate application behavior, or execute arbitrary code. The vulnerability is particularly concerning in server-side applications where mixin-deep is used for configuration merging, data processing, or object composition. According to ATT&CK framework, this vulnerability maps to T1059.007 for script injection and T1211 for exploitation for defense evasion. Applications using vulnerable versions of mixin-deep are at risk of being exploited through various attack vectors including web application requests, API endpoints, or any input processing that utilizes the affected package.
Mitigation strategies for CVE-2019-10746 require immediate remediation through version updates to mixin-deep 1.3.2 or 2.0.1, which contain the necessary patches to prevent prototype pollution. Organizations should conduct comprehensive dependency audits to identify all instances of vulnerable package versions and ensure proper version pinning in package.json files. Additional protective measures include implementing input validation layers, using defensive programming practices such as Object.freeze or Object.seal on prototype objects, and employing runtime monitoring to detect anomalous prototype modifications. The vulnerability demonstrates the importance of secure coding practices and proper input validation, particularly when dealing with object merging and manipulation functions. Security teams should also consider implementing dependency scanning tools that can automatically detect and alert on vulnerable package versions to prevent exploitation.