CVE-2025-7783 is a critical security vulnerability classified under CWE-330, which concerns the use of insufficiently random values. This vulnerability specifically affects the 'form-data' JavaScript library, versions prior to 2.5.4, versions 3.0.0 through 3.0.3, and versions 4.0.0 through 4.0.3. The root cause lies in the generation or handling of random values within the library's 'lib/form_data.js' file, which are insufficiently random and thus predictable or manipulable. This weakness enables an attacker to perform HTTP Parameter Pollution (HPP) attacks. HPP involves injecting multiple HTTP parameters with the same name into a single request, potentially causing the server to process unexpected or malicious input. The vulnerability has a CVSS 4.0 base score of 9.4, indicating a critical severity level. The vector metrics show that the attack can be performed remotely over the network (AV:N), requires high attack complexity (AC:H), does not require authentication (PR:N), and does not require user interaction (UI:N). However, the impact on confidentiality, integrity, and availability is high (VC:H, VI:H, VA:N), and the scope is high (SC:H), meaning the vulnerability affects components beyond the vulnerable library itself. No known exploits are currently reported in the wild, and no official patches or fixes have been linked yet. The vulnerability's exploitation could allow attackers to manipulate HTTP parameters, potentially bypassing security controls, injecting malicious data, or causing unintended application behavior, which could lead to data leakage, unauthorized actions, or denial of service depending on the application context.

For European organizations, the impact of CVE-2025-7783 can be significant, especially for those relying on web applications or services that utilize the vulnerable versions of the 'form-data' library. Since the vulnerability enables HTTP Parameter Pollution, attackers could manipulate request parameters to bypass input validation, authentication, or authorization mechanisms, potentially leading to unauthorized data access or modification. This could compromise sensitive personal data protected under GDPR, leading to regulatory penalties and reputational damage. Additionally, the ability to disrupt application logic or inject malicious payloads could result in service outages or data integrity issues, impacting business continuity. Given the critical severity and the lack of required authentication or user interaction, the threat is particularly concerning for public-facing web services and APIs. Organizations in sectors such as finance, healthcare, e-commerce, and government services in Europe, which handle sensitive data and are subject to strict compliance requirements, may face heightened risks. The vulnerability could also be leveraged as part of multi-stage attacks, increasing the overall threat landscape.

To mitigate CVE-2025-7783 effectively, European organizations should: 1) Immediately identify and inventory all applications and services using the affected versions of the 'form-data' library. 2) Apply updates or patches as soon as they become available from the library maintainers; if no official patch exists yet, consider upgrading to a non-affected version or applying community-provided fixes after thorough testing. 3) Implement strict input validation and parameter parsing on the server side to detect and reject duplicate or suspicious HTTP parameters, thereby mitigating HTTP Parameter Pollution attempts. 4) Employ Web Application Firewalls (WAFs) with rules specifically designed to detect and block HPP attack patterns. 5) Conduct thorough security testing, including fuzzing and penetration testing focused on HTTP parameter handling, to identify and remediate related weaknesses. 6) Monitor application logs and network traffic for anomalies indicative of HPP exploitation attempts. 7) Educate development teams about secure coding practices related to randomness and parameter handling to prevent similar vulnerabilities in the future. 8) Consider implementing Content Security Policy (CSP) and other defense-in-depth measures to reduce the impact of potential exploitation.