CVE-2025-49065 is a high-severity vulnerability classified as CWE-79, which corresponds to Improper Neutralization of Input During Web Page Generation, commonly known as Cross-site Scripting (XSS). This vulnerability affects the BestiaDurmiente Visit Counter product, specifically versions up to 1.0. The flaw allows an attacker to inject malicious scripts that are stored persistently within the application, leading to Stored XSS attacks. Stored XSS occurs when malicious input is saved by the application and then served to other users without proper sanitization or encoding, enabling attackers to execute arbitrary JavaScript in the context of victims' browsers. According to the CVSS v3.1 score of 7.1 (high), the vulnerability is remotely exploitable over the network without requiring privileges but does require user interaction, such as a victim visiting a crafted webpage. The scope is changed (S:C), indicating that exploitation can affect resources beyond the vulnerable component. The impact includes low confidentiality, integrity, and availability losses, meaning attackers can steal limited sensitive information, manipulate some data, or cause partial service disruption. No patches are currently available, and no known exploits have been reported in the wild. The vulnerability likely arises from insufficient input validation or output encoding in the Visit Counter's web page generation logic, allowing malicious payloads to be embedded and executed in users' browsers.

For European organizations using BestiaDurmiente Visit Counter, this vulnerability poses a significant risk primarily to web application security and user trust. Stored XSS can lead to session hijacking, credential theft, defacement, or redirection to malicious sites, potentially compromising user accounts and sensitive data. Organizations that rely on this Visit Counter for website analytics or visitor tracking may inadvertently expose their users to attacks, damaging reputation and violating data protection regulations such as GDPR. The ability to execute scripts in users' browsers can also facilitate further attacks like phishing or malware delivery. Although the confidentiality and integrity impacts are rated low, the combined effect with availability impact and scope change means attackers can affect multiple users and possibly escalate attacks within the affected environment. This is particularly concerning for sectors with high web traffic or sensitive user data, such as e-commerce, finance, or government portals in Europe.

Given the absence of official patches, European organizations should implement immediate compensating controls. First, disable or remove the BestiaDurmiente Visit Counter from websites until a secure version is released. If removal is not feasible, apply strict input validation and output encoding on all user-supplied data related to the Visit Counter, using established libraries or frameworks that prevent XSS. Employ Content Security Policy (CSP) headers to restrict script execution and reduce the impact of potential XSS payloads. Regularly monitor web application logs for suspicious input patterns or anomalous user behavior indicative of exploitation attempts. Educate web developers and administrators on secure coding practices to prevent similar vulnerabilities. Finally, prepare to deploy patches promptly once available and conduct thorough security testing of the Visit Counter integration.