CVE-2020-28276 in deep-set
Summary
by MITRE • 12/30/2020
Prototype pollution vulnerability in 'deep-set' versions 1.0.0 through 1.0.1 allows attacker to cause a denial of service and may lead to remote code execution.
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Analysis
by VulDB Data Team • 12/30/2020
Prototype pollution vulnerabilities occur when an application fails to properly validate or sanitize user input that is used to modify object prototypes. In the case of deep-set versions 1.0.0 through 1.0.1, this vulnerability specifically affects how the library handles nested object property assignments. When an attacker provides malicious input containing prototype-polluting keys such as _proto_ or constructor, the library's set function fails to properly sanitize these inputs, allowing the attacker to modify the prototype of objects. This flaw stems from a lack of proper input validation and sanitization mechanisms within the library's core functionality, creating a path for attackers to inject malicious properties into object prototypes. The vulnerability is categorized under CWE-471 which specifically addresses the modification of the program's control flow through manipulation of object prototypes. From an operational perspective, this vulnerability can lead to severe consequences including denial of service attacks where the application crashes due to prototype modifications, and in more sophisticated scenarios, may enable remote code execution through prototype chain poisoning techniques. Attackers can leverage this vulnerability by crafting payloads that exploit the prototype pollution to manipulate object behavior, potentially leading to privilege escalation or arbitrary code execution within the application context. The ATT&CK framework categorizes this under T1059.007 for script injection and T1566 for phishing with malicious attachments, as attackers often use prototype pollution as part of broader exploitation chains. The impact extends beyond simple denial of service to include potential data corruption, unauthorized access to system resources, and complete system compromise when combined with other vulnerabilities. Organizations using affected versions of deep-set should immediately upgrade to patched versions and implement input validation measures to prevent malicious prototype pollution attempts. Additionally, runtime protections such as prototype lockdown mechanisms and strict input sanitization should be deployed to mitigate the risk of exploitation. The vulnerability demonstrates the critical importance of proper input validation in JavaScript applications and highlights how seemingly innocuous library functions can become attack vectors when prototype pollution is not adequately addressed. Security teams should conduct thorough audits of their dependency trees to identify and remediate similar vulnerabilities in other libraries that may be susceptible to prototype pollution attacks.