CVE-2025-4415 is a Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the Drupal Piwik PRO module versions prior to 1.3.2, specifically from version 0.0.0 up to but not including 1.3.2. This vulnerability arises due to improper neutralization of input during web page generation, allowing malicious actors to inject and execute arbitrary scripts in the context of a victim's browser session. The vulnerability is exploitable remotely (AV:N), requires low attack complexity (AC:L), but needs the attacker to have high privileges (PR:H) and user interaction (UI:R). The scope is changed (S:C), indicating that the vulnerability affects resources beyond the security scope of the vulnerable component. The impact on confidentiality and integrity is low (C:L, I:L), with no impact on availability (A:N). This means an attacker could potentially steal or manipulate data accessible to the user or perform actions on behalf of the user, but cannot disrupt service availability. No known exploits are currently observed in the wild, and no patches or fixes have been linked yet. The vulnerability was published on May 21, 2025, and is rated medium severity with a CVSS 3.1 score of 4.8. The vulnerability specifically targets the Piwik PRO analytics integration within Drupal, which is used for web analytics and user behavior tracking.

For European organizations, this vulnerability poses a moderate risk primarily to web applications leveraging Drupal with the Piwik PRO module for analytics. Successful exploitation could lead to session hijacking, unauthorized actions performed in the context of authenticated users, or theft of sensitive information such as cookies or tokens. Given the high privilege requirement for the attacker, the threat is more relevant in scenarios where internal users or compromised accounts are involved. The impact on confidentiality and integrity, although low, could still lead to data leakage or manipulation, which is critical under GDPR regulations. Additionally, the scope change indicates potential cross-domain or cross-component impact, which could complicate incident response. Organizations relying on Piwik PRO for compliance reporting or customer analytics might face data integrity issues, affecting decision-making and regulatory compliance. The lack of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure.

European organizations should prioritize upgrading the Drupal Piwik PRO module to version 1.3.2 or later once available, as this will likely contain the necessary patches. Until then, organizations should implement strict input validation and output encoding on all user-supplied data within the affected components to prevent script injection. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. Conduct thorough access control reviews to minimize the number of users with high privileges, reducing the attack surface. Monitor web application logs for unusual activities indicative of XSS exploitation attempts, such as suspicious script payloads in requests. Additionally, educate users about the risks of interacting with untrusted links or content within the application. Implement web application firewalls (WAF) with rules tailored to detect and block XSS payloads targeting Drupal and Piwik PRO. Finally, maintain an incident response plan that includes procedures for handling XSS incidents, including session invalidation and forensic analysis.