CVE-2025-57321 is a critical Prototype Pollution vulnerability identified in the util-deps.addFileDepend function of the magix-combine-ex library, affecting all versions up to 1.2.10. Prototype Pollution occurs when an attacker is able to inject or modify properties on JavaScript's Object.prototype, which can lead to unexpected behavior in applications relying on this object. In this case, the vulnerability allows an unauthenticated attacker to supply a crafted payload that manipulates Object.prototype, resulting in a denial of service (DoS) condition as a minimum impact. The vulnerability has a CVSS v3.1 base score of 9.8, indicating critical severity, with an attack vector that is network-based (AV:N), requiring no privileges (PR:N) and no user interaction (UI:N). The impact affects confidentiality, integrity, and availability (C:H/I:H/A:H), meaning exploitation could lead to full compromise of affected systems. Although no known exploits are currently reported in the wild, the high severity and ease of exploitation make this a significant threat. The vulnerability is categorized under CWE-1321, which relates to improper handling of prototype pollution in JavaScript environments. The magix-combine-ex library is typically used in web development environments for module combination and dependency management, so applications leveraging this library could be exposed to this vulnerability if they use affected versions. No official patches or fixes have been linked yet, indicating that affected organizations should prioritize mitigation and monitoring efforts.

For European organizations, the impact of CVE-2025-57321 could be substantial, especially for those relying on magix-combine-ex in their web application development or deployment pipelines. Exploitation could lead to denial of service, disrupting business-critical web services and potentially causing downtime. Given the vulnerability's ability to affect confidentiality and integrity, attackers might also leverage prototype pollution to escalate attacks, such as injecting malicious code or bypassing security controls, which could lead to data breaches or further compromise. This is particularly concerning for sectors with stringent data protection requirements under GDPR, such as finance, healthcare, and government services. The critical severity and network-based attack vector mean that attackers can exploit this remotely without authentication or user interaction, increasing the risk of widespread exploitation if the vulnerability is not addressed promptly. Additionally, the lack of known exploits in the wild currently provides a window for proactive defense, but organizations should act swiftly to prevent potential future attacks.

1. Immediate audit of all applications and development environments to identify usage of magix-combine-ex versions up to 1.2.10. 2. If possible, upgrade to a patched or newer version of magix-combine-ex once available; if no patch exists yet, consider temporary removal or replacement of the library with alternative solutions. 3. Implement strict input validation and sanitization for any data processed through util-deps.addFileDepend or related functions to prevent malicious payload injection. 4. Employ runtime application self-protection (RASP) or web application firewalls (WAFs) configured to detect and block suspicious payloads targeting prototype pollution patterns. 5. Monitor application logs and network traffic for anomalous behavior indicative of prototype pollution attempts or denial of service conditions. 6. Educate development teams on secure coding practices related to JavaScript prototype handling to prevent similar vulnerabilities in custom code. 7. Establish incident response plans specifically addressing prototype pollution exploitation scenarios to enable rapid containment and recovery.