CVE-2020-28270 in object-hierarchy-access
Summary
by MITRE • 11/12/2020
Prototype pollution vulnerability in 'object-hierarchy-access' versions 0.2.0 through 0.32.0 allows attacker to cause a denial of service and may lead to remote code execution.
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Analysis
by VulDB Data Team • 12/06/2020
The vulnerability identified as CVE-2020-28270 represents a critical prototype pollution flaw within the object-hierarchy-access npm package version range 0.2.0 through 0.32.0. This type of vulnerability occurs when an application fails to properly validate or sanitize user-supplied input that is used to modify object prototypes, creating a dangerous attack vector that can compromise application integrity and security. The object-hierarchy-access package is commonly used in Node.js applications for accessing nested object properties through string-based paths, making it a frequent target for attackers seeking to exploit prototype pollution vulnerabilities in web applications.
The technical flaw stems from improper handling of object property assignment operations within the package's implementation. When user-provided input is processed without adequate validation, attackers can inject malicious property names that pollute the Object.prototype, thereby affecting all objects in the application's execution context. This occurs because the vulnerable code does not properly distinguish between legitimate object properties and prototype pollution attempts, allowing attackers to manipulate the prototype chain and potentially override critical methods or properties. The vulnerability specifically manifests when the package processes hierarchical access patterns that include special characters or sequences that can be interpreted as prototype manipulation attempts, creating a pathway for attackers to gain unauthorized control over object behavior.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable full remote code execution in certain environments. Attackers can leverage prototype pollution to manipulate object behavior in ways that may allow them to bypass security controls, inject malicious code, or cause applications to behave unpredictably. The severity of this vulnerability is particularly concerning because it can affect applications across various domains including web servers, backend services, and microservices that rely on this package for object property access. When exploited, the vulnerability can result in complete system compromise, data exfiltration, or service disruption that affects multiple users and applications depending on the affected system's architecture.
Mitigation strategies for CVE-2020-28270 should prioritize immediate package updates to versions that have addressed the prototype pollution vulnerability through proper input validation and sanitization. Organizations must conduct comprehensive dependency audits to identify all systems using vulnerable versions of object-hierarchy-access and ensure proper patching procedures are implemented across their infrastructure. Additional protective measures include implementing strict input validation at application boundaries, using secure coding practices that prevent prototype pollution, and deploying runtime monitoring solutions that can detect anomalous object property modifications. The vulnerability aligns with CWE-471 which specifically addresses the issue of incorrect behavior in prototype pollution scenarios, and corresponds to ATT&CK technique T1059.006 for remote code execution through prototype manipulation. Organizations should also consider implementing sandboxing techniques and application whitelisting to limit the potential impact of prototype pollution attacks, while maintaining detailed logging of object property access patterns to detect suspicious behavior and ensure rapid incident response capabilities.