CVE-2025-70890 is a stored cross-site scripting vulnerability identified in Cyber Cafe Management System version 1.0. The vulnerability exists in the add-users.php endpoint, specifically within the username parameter, which fails to properly sanitize or encode user input. An authenticated attacker can exploit this by injecting arbitrary JavaScript code into the username field when adding users. Because the injected script is stored persistently on the server, it executes in the context of any user who views the affected page, leading to potential compromise of user sessions, theft of sensitive information, or execution of unauthorized actions on behalf of the victim. Stored XSS is particularly dangerous as it affects multiple users and can be leveraged for widespread attacks such as spreading malware or phishing. The attack requires the attacker to have valid credentials, which somewhat limits the attack vector to insiders or compromised accounts. No patches or fixes are currently linked, and no known exploits have been reported in the wild, indicating the vulnerability may not yet be actively exploited but remains a significant risk. The lack of a CVSS score necessitates an assessment based on the nature of the vulnerability, its persistence, and the potential impact on confidentiality, integrity, and availability.

For European organizations, this vulnerability could lead to significant security breaches if Cyber Cafe Management System v1.0 is in use, especially in environments where multiple users access the system, such as internet cafes, libraries, or educational institutions. The stored XSS can allow attackers to hijack sessions, steal credentials, or perform actions on behalf of legitimate users, potentially leading to data breaches or unauthorized system modifications. The requirement for authentication reduces the risk from external attackers but raises concerns about insider threats or compromised accounts. The impact on confidentiality is high due to potential data theft, integrity can be compromised through unauthorized actions, and availability might be affected if attackers disrupt normal operations. Given the persistent nature of stored XSS, multiple users can be affected over time, amplifying the damage. European organizations with limited security monitoring or outdated systems are particularly vulnerable. The absence of known exploits suggests a window for proactive mitigation before widespread exploitation occurs.

To mitigate CVE-2025-70890, organizations should implement strict input validation and output encoding on the username parameter within add-users.php to prevent injection of malicious scripts. Employing a web application firewall (WAF) with rules to detect and block XSS payloads can provide an additional layer of defense. Restrict user privileges to the minimum necessary to reduce the risk of authenticated attackers exploiting the vulnerability. Conduct regular security audits and code reviews focusing on input handling and sanitization. If patching is not immediately available, consider disabling or restricting access to the vulnerable add-users.php endpoint. Educate users and administrators about the risks of stored XSS and monitor logs for suspicious activities indicative of exploitation attempts. Implement Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. Finally, maintain an incident response plan to quickly address any exploitation events.