CVE-2024-50406 is a cross-site scripting (XSS) vulnerability identified in QNAP Systems Inc.'s License Center product, specifically affecting versions 1.9.x prior to 1.9.49. The vulnerability is classified under CWE-79, which pertains to improper neutralization of input during web page generation, allowing attackers to inject malicious scripts. In this case, remote attackers who have already gained some level of user access to the License Center application could exploit this XSS flaw to bypass security mechanisms or read sensitive application data. The vulnerability requires low privileges (PR:L), user interaction (UI:A), and has a high attack complexity (AC:H), indicating that exploitation is not trivial but possible under certain conditions. The CVSS 4.0 base score is 2.0, reflecting a low severity rating. The impact on confidentiality, integrity, and availability is limited (all low), and the scope is limited to the vulnerable component. No known exploits are currently reported in the wild. The vendor has addressed this vulnerability in License Center version 1.9.49 and later, recommending users to update accordingly. The vulnerability's exploitation could lead to session hijacking, unauthorized data access, or manipulation of the web interface, but only if an attacker has already obtained user-level access and can trick a user into interacting with malicious content.

For European organizations using QNAP License Center version 1.9.x, this vulnerability poses a limited but non-negligible risk. Since exploitation requires prior user access and user interaction, the threat is primarily to internal users or attackers who have already compromised credentials or sessions. Potential impacts include unauthorized disclosure of application data and bypassing of security controls within the License Center, which could lead to further lateral movement or privilege escalation within the network. Organizations relying on License Center for license management and related administrative functions could face operational disruptions or data leakage. However, the low severity and complexity reduce the likelihood of widespread exploitation. Still, in highly regulated sectors such as finance, healthcare, or critical infrastructure within Europe, even low-severity vulnerabilities can have compliance and reputational consequences if exploited.

European organizations should prioritize upgrading QNAP License Center to version 1.9.49 or later, where the vulnerability has been fixed. Beyond patching, organizations should implement strict access controls to limit user privileges within the License Center, minimizing the risk of attackers gaining initial access. Employing web application firewalls (WAFs) with rules to detect and block XSS payloads can provide an additional layer of defense. Security awareness training should emphasize the risks of phishing and social engineering, which could facilitate the user interaction needed for exploitation. Regular security assessments and code reviews of web applications integrated with License Center can help identify and remediate similar vulnerabilities. Monitoring logs for unusual activity related to License Center access may help detect attempted exploitation early.