CVE-2025-57330 is a high-severity Prototype Pollution vulnerability found in the web3-core-subscriptions package, specifically in the attachToObject function in versions 1.10.4 and earlier. This package is used to manage web3 subscriptions, which are integral to interacting with blockchain networks via web3.js libraries. Prototype Pollution vulnerabilities occur when an attacker can inject or modify properties on JavaScript's Object.prototype, which affects all objects inheriting from it. In this case, an attacker can supply a crafted payload to the vulnerable function, causing properties to be injected into Object.prototype. This manipulation can lead to unexpected behavior in the application, primarily resulting in denial of service (DoS) conditions. The vulnerability has a CVSS 3.1 base score of 7.5, indicating a high severity level. The vector indicates that the attack can be performed remotely (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and affects availability (A:H) without impacting confidentiality or integrity. Although no known exploits are currently reported in the wild, the ease of exploitation and the potential for service disruption make this a significant risk. The vulnerability is categorized under CWE-1321, which relates to improper handling of prototype pollution in JavaScript environments. No patches or fixes have been linked yet, so affected users must be vigilant and consider mitigation strategies. Since web3-core-subscriptions is a component used in blockchain-related applications, this vulnerability could impact decentralized applications (dApps), blockchain infrastructure services, and any systems relying on this package for subscription management to blockchain events or data streams.

For European organizations, the impact of CVE-2025-57330 can be substantial, especially those involved in blockchain technology, fintech, and decentralized finance (DeFi) sectors. A successful exploitation can cause denial of service, disrupting critical blockchain event subscriptions and potentially halting transaction monitoring, smart contract event handling, or other blockchain-dependent operations. This disruption can affect service availability, leading to financial losses, degraded user trust, and operational downtime. Organizations providing blockchain infrastructure or services to European customers may face compliance and regulatory scrutiny if service disruptions affect data integrity or availability under regulations like GDPR or the Digital Operational Resilience Act (DORA). Furthermore, the vulnerability could be leveraged as part of a larger attack chain to destabilize blockchain-based applications or platforms, impacting the broader European blockchain ecosystem. Given the increasing adoption of blockchain technology across Europe, especially in countries like Germany, the Netherlands, and Switzerland, the threat poses a risk to both private enterprises and public sector initiatives utilizing blockchain for transparency, identity management, or supply chain tracking.

1. Immediate mitigation involves auditing and updating the web3-core-subscriptions package to a version that addresses this vulnerability once available. Since no patch links are currently provided, organizations should monitor official repositories and security advisories for updates. 2. Implement input validation and sanitization on all data passed to the attachToObject function or any related subscription management functions to prevent malicious payloads from reaching the vulnerable code. 3. Employ runtime protection mechanisms such as JavaScript sandboxing or prototype pollution detection tools that can monitor and block unauthorized modifications to Object.prototype. 4. Use dependency scanning tools integrated into CI/CD pipelines to detect vulnerable package versions and prevent deployment of affected software. 5. For critical blockchain infrastructure, consider isolating subscription management components and applying strict access controls and network segmentation to limit exposure. 6. Conduct thorough security testing, including fuzzing and penetration testing focused on prototype pollution vectors, to identify and remediate similar vulnerabilities proactively. 7. Maintain incident response readiness to quickly address potential denial of service incidents stemming from exploitation attempts.