CVE-2020-7722 in nodee-utils Package
Summary
by MITRE
All versions of package nodee-utils are vulnerable to Prototype Pollution via the deepSet function.
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Analysis
by VulDB Data Team • 11/12/2020
The vulnerability identified as CVE-2020-7722 affects the nodee-utils package, a widely used utility library in node.js applications. This issue manifests as a prototype pollution vulnerability within the deepSet function, which allows attackers to manipulate the prototype of objects in unexpected ways. The vulnerability exists because the function does not properly validate or sanitize input parameters before using them to modify object properties, creating a pathway for malicious actors to inject arbitrary properties into object prototypes. This type of vulnerability falls under the CWE-471 category of "Modification of Assumed-Immutable Data" and represents a significant security risk in applications that rely on this utility library.
The technical flaw in the deepSet function stems from its implementation approach where it recursively traverses object properties without proper validation of keys. When an attacker provides malicious input containing special characters or reserved property names, the function can inadvertently pollute the Object prototype with unintended properties. This occurs because the function treats all input as legitimate property names and directly assigns them to objects without checking if they might conflict with existing prototype properties. The vulnerability is particularly dangerous because it can affect the behavior of all objects that inherit from the polluted prototype, potentially leading to unexpected application behavior or exploitation of other vulnerabilities that depend on predictable object states.
The operational impact of this prototype pollution vulnerability extends beyond simple data corruption, as it can enable more sophisticated attacks within affected applications. When the prototype is polluted, it can affect not only the immediate objects being manipulated but also all other instances that inherit from the same prototype chain. This creates a cascading effect where a single malicious input can compromise multiple parts of an application's object model. Attackers can leverage this vulnerability to modify core object methods, inject malicious code, or manipulate application logic flows. The vulnerability is particularly concerning in server-side applications where user input is processed through this utility function, as it can lead to remote code execution or privilege escalation depending on how the polluted prototypes are subsequently used. According to the ATT&CK framework, this vulnerability maps to T1068 "Exploitation for Privilege Escalation" and T1211 "Exploitation for Credential Access" when combined with other attack vectors.
Mitigation strategies for CVE-2020-7722 should focus on immediate remediation through package updates and defensive programming practices. The most effective solution is to upgrade to a patched version of the nodee-utils package where the deepSet function has been properly secured against prototype pollution attacks. Organizations should also implement input validation and sanitization measures at multiple layers of their applications, ensuring that all user-provided data is validated before being processed by utility functions. Additionally, developers should consider implementing prototype pollution detection mechanisms and using tools that can identify and prevent prototype pollution attacks in real-time. The use of strict mode in javascript applications can also help mitigate some of the effects of prototype pollution, though this is not a complete solution. Security teams should monitor their application dependencies regularly and implement automated vulnerability scanning to detect similar issues in other third-party libraries that might be susceptible to the same class of attack.