CVE-2025-57329 is a high-severity Prototype Pollution vulnerability found in the web3-core-method package, specifically in the attachToObject function of versions 1.10.4 and earlier. This package is integral to the web3 ecosystem, which is widely used for interacting with Ethereum blockchain modules and other decentralized applications. Prototype Pollution vulnerabilities occur when an attacker can inject or modify properties on JavaScript's Object.prototype, thereby affecting all objects that inherit from it. In this case, the vulnerability allows an unauthenticated remote attacker to supply a crafted payload that manipulates the prototype chain, leading to unexpected behavior in the application. The primary impact identified is a denial of service (DoS), where the application or service using the vulnerable package may crash or become unresponsive due to corrupted object states or infinite loops triggered by the polluted prototype. The CVSS score of 7.5 (high) reflects that the vulnerability can be exploited remotely without authentication or user interaction, with a network attack vector and low attack complexity. While confidentiality and integrity impacts are not observed, the availability impact is significant. No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that mitigation may require manual code review or updates once available. The vulnerability is classified under CWE-1321, which relates to improper handling of prototype pollution in JavaScript environments.

For European organizations, the impact of this vulnerability can be substantial, especially for those leveraging blockchain technologies, decentralized finance (DeFi) platforms, or other web3-based applications that depend on the web3-core-method package. A successful exploitation could lead to service outages, disrupting business operations, customer transactions, and trust in blockchain services. Given the increasing adoption of blockchain in sectors such as finance, supply chain, and public services across Europe, availability disruptions could have cascading effects on critical infrastructure and financial markets. Additionally, denial of service conditions could be exploited as part of larger multi-vector attacks, potentially masking other malicious activities. Organizations relying on third-party services or software that incorporate this package may also face indirect impacts. The lack of authentication and user interaction requirements lowers the barrier for attackers, increasing the risk of widespread exploitation if the vulnerability becomes publicly known or weaponized.

European organizations should immediately audit their software dependencies to identify usage of web3-core-method version 1.10.4 or earlier. Until an official patch is released, developers should consider implementing input validation and sanitization to prevent malicious payloads from reaching the attachToObject function. Employing runtime monitoring and anomaly detection for unusual prototype modifications can help detect exploitation attempts. Organizations should also isolate blockchain-related services to limit the blast radius of potential DoS attacks. Engaging with vendors and open-source maintainers to prioritize patch development and applying updates promptly once available is critical. Additionally, incorporating Web Application Firewalls (WAFs) with custom rules to block suspicious payloads targeting prototype pollution vectors can provide a temporary protective layer. Regular security assessments and penetration testing focused on prototype pollution scenarios are recommended to ensure resilience against similar vulnerabilities.