CVE-2025-64675 is a cross-site scripting (XSS) vulnerability classified under CWE-79 affecting Microsoft Azure Cosmos DB, a globally used multi-model database service. The vulnerability stems from improper neutralization of user-supplied input during web page generation, allowing attackers to inject malicious scripts into web pages rendered by the service. This flaw enables unauthorized attackers to conduct spoofing attacks over a network by tricking users into executing malicious scripts, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The CVSS 3.1 base score of 8.3 reflects a high severity, with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but user interaction is necessary (UI:R). The impact on confidentiality and integrity is high, while availability impact is low. The vulnerability does not require authentication, increasing its risk profile. Although no exploits are currently known in the wild, the widespread use of Azure Cosmos DB in cloud environments makes this a significant threat. The lack of specified affected versions and absence of patch links suggests that Microsoft may be preparing or has recently released mitigations. This vulnerability highlights the critical need for secure input handling and output encoding in cloud services to prevent XSS attacks that can compromise user trust and data security.

For European organizations, this vulnerability poses a substantial risk to data confidentiality and integrity, especially for those relying on Azure Cosmos DB for critical applications and data storage. Successful exploitation could lead to unauthorized access to sensitive information, session hijacking, and execution of malicious actions under the guise of legitimate users. This can result in data breaches, regulatory non-compliance (e.g., GDPR violations), reputational damage, and financial losses. The requirement for user interaction means phishing or social engineering campaigns could be used to trigger the exploit, increasing the attack surface. Given the cloud-based nature of Azure Cosmos DB, the impact can extend across multiple sectors including finance, healthcare, government, and technology. The availability impact is low, so denial-of-service is less of a concern, but the integrity and confidentiality risks are critical. European organizations with extensive cloud deployments and those integrating Cosmos DB into customer-facing applications are particularly vulnerable.

1. Apply any official patches or updates released by Microsoft for Azure Cosmos DB as soon as they become available. 2. Implement strict input validation and sanitization on all user inputs that interact with Azure Cosmos DB web interfaces or APIs to prevent injection of malicious scripts. 3. Employ robust output encoding techniques to neutralize any potentially dangerous characters before rendering content in web pages. 4. Use Content Security Policy (CSP) headers to restrict the execution of untrusted scripts in browsers accessing affected services. 5. Educate users and administrators about the risks of phishing and social engineering attacks that could exploit this vulnerability, emphasizing caution with unsolicited links or content. 6. Monitor logs and network traffic for unusual activities or attempts to exploit XSS vectors related to Cosmos DB. 7. Consider implementing web application firewalls (WAFs) with rules designed to detect and block XSS payloads targeting Azure services. 8. Review and limit permissions and access controls to minimize exposure if an account is compromised. 9. Conduct regular security assessments and penetration testing focusing on web application security around Cosmos DB integrations.