CVE-2022-41714 is a medium-severity prototype pollution vulnerability found in version 1.0.1 of the fastest-json-copy library, a JavaScript utility used to copy JSON objects efficiently. The vulnerability arises because the library does not properly validate incoming JSON keys, allowing an attacker to manipulate the special '__proto__' property of JavaScript objects. By modifying this property, an attacker can alter the prototype of objects, effectively injecting or changing properties that affect all objects inheriting from that prototype. This can lead to unexpected behavior, including the potential for integrity violations within the application. The vulnerability does not impact confidentiality or availability directly, and no authentication or user interaction is required for exploitation. The CVSS 3.1 base score is 5.3 (medium), reflecting the network attack vector, low attack complexity, no privileges required, and no user interaction. Although no known exploits have been reported in the wild, the flaw represents a risk in environments where fastest-json-copy 1.0.1 is used to process untrusted JSON input, especially in server-side JavaScript applications. Prototype pollution can be leveraged as a stepping stone for more complex attacks, such as bypassing security controls or causing application logic errors.

For European organizations, the impact of this vulnerability depends largely on the extent to which fastest-json-copy 1.0.1 is integrated into their software stacks, particularly in backend JavaScript environments like Node.js. If exploited, attackers could manipulate application behavior by injecting or modifying object properties, potentially leading to data integrity issues or enabling further attacks such as privilege escalation or denial of service through corrupted application state. While the vulnerability does not directly expose sensitive data or cause service outages, the integrity compromise can undermine trust in application outputs and may facilitate more severe chained attacks. Organizations in sectors with high reliance on JavaScript-based services—such as finance, e-commerce, and critical infrastructure—may face increased risk if this library is used without proper validation. Additionally, the lack of authentication and user interaction requirements means that remote attackers can exploit this vulnerability over the network, increasing the attack surface. However, the absence of known exploits in the wild suggests that immediate widespread impact is limited, though proactive mitigation is advisable.

European organizations should first identify any usage of fastest-json-copy version 1.0.1 within their codebases or third-party dependencies. Since no official patch links are provided, organizations should consider upgrading to a later, patched version if available or replacing fastest-json-copy with alternative JSON copying libraries that properly sanitize input keys. In the interim, implement strict input validation and sanitization to reject or neutralize JSON objects containing '__proto__' or other prototype-related keys before processing. Employ runtime protections such as object freezing or sealing to prevent prototype modification where feasible. Additionally, conduct thorough code reviews and static analysis to detect prototype pollution risks. Security teams should monitor for suspicious application behavior indicative of prototype pollution exploitation and maintain updated threat intelligence feeds. Finally, incorporate dependency management tools that alert on vulnerable packages to prevent reintroduction of this or similar vulnerabilities.