CVE-2023-2972 in utils
Summary
by MITRE • 05/30/2023
Prototype Pollution in GitHub repository antfu/utils prior to 0.7.3.
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Analysis
by VulDB Data Team • 07/14/2025
The vulnerability CVE-2023-2972 represents a prototype pollution flaw discovered in the antfu/utils library, a popular utility collection for javascript development. This issue affects versions prior to 0.7.3 and stems from improper handling of object property assignment during deep cloning operations. The flaw allows attackers to manipulate the prototype chain of objects by injecting malicious properties through user-controlled input, potentially leading to unexpected behavior in applications that rely on this library for data manipulation and object cloning.
The technical implementation of this vulnerability occurs when the library processes objects containing properties that could alter the Object.prototype directly. Specifically, when the utility functions attempt to merge or clone objects, they fail to properly sanitize or validate property names that might contain special characters or sequences that could target prototype properties. This creates an avenue for attackers to inject malicious properties into the prototype chain, which can then be exploited by subsequent code that iterates over object properties or relies on prototype-based inheritance patterns. The vulnerability is particularly concerning because it operates at the core level of object manipulation where many applications depend on predictable behavior.
The operational impact of CVE-2023-2972 extends beyond simple code execution as it can enable various attack vectors including denial of service, data manipulation, and potentially remote code execution in certain contexts. When exploited, prototype pollution can cause applications to behave unpredictably, leading to crashes or unexpected program flow. The vulnerability is especially dangerous in server-side javascript environments where applications might process user input through this library, as it can lead to privilege escalation or data corruption. Additionally, the cascading effects of prototype pollution can manifest in other parts of the application stack where prototype-based logic is relied upon, making the attack surface potentially much larger than the initial vulnerable library.
Mitigation strategies for this vulnerability primarily involve updating to version 0.7.3 or later of the antfu/utils library where the prototype pollution issue has been addressed through proper input validation and sanitization of object properties during cloning operations. Security teams should also implement comprehensive dependency scanning to identify applications using vulnerable versions and establish monitoring for unusual object property assignments that might indicate exploitation attempts. The fix typically involves implementing stricter property name validation and ensuring that object merging functions properly isolate user-controlled data from prototype properties. Organizations should also consider implementing runtime protections such as prototype lockdown mechanisms and regular security audits of their javascript dependencies to prevent similar issues in other libraries.
This vulnerability aligns with CWE-471, which describes the insertion of data into the prototype of an object, and maps to attack techniques in the ATT&CK framework under T1211 for lateral movement through code injection and T1059 for command and scripting interpreter usage. The remediation approach follows security best practices outlined in OWASP Top 10 and NIST guidelines for dependency management and input validation, emphasizing the critical importance of maintaining up-to-date libraries and implementing proper sanitization of user inputs in javascript applications.