CVE-2025-50858 is a reflected Cross-Site Scripting (XSS) vulnerability identified in the Easy Hosting Control Panel (EHCP) version 20.04.1.b, specifically within the 'List MySQL Databases' function. This vulnerability arises due to insufficient sanitization of the 'action' parameter, which allows an authenticated attacker to inject and execute arbitrary JavaScript code in the context of the victim's browser session. Reflected XSS vulnerabilities occur when malicious input is immediately returned in the server's response without proper encoding or validation, enabling attackers to craft URLs or requests that execute scripts when visited by legitimate users. In this case, the attacker must be authenticated to the EHCP system, which reduces the attack surface but still poses significant risk within environments where multiple users have access. The vulnerability is classified under CWE-79, which covers improper neutralization of input leading to XSS. The CVSS v3.1 base score is 6.1 (medium severity), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but user interaction required (UI:R), scope changed (S:C), and low impact on confidentiality and integrity (C:L/I:L) with no impact on availability (A:N). No known exploits are reported in the wild, and no patches have been linked yet. The reflected XSS can be leveraged to steal session cookies, perform actions on behalf of the user, or deliver further payloads, potentially leading to privilege escalation or data leakage within the hosting control panel environment.

For European organizations using EHCP 20.04.1.b, this vulnerability could lead to unauthorized execution of scripts within the control panel interface, potentially compromising administrative sessions or user data. Since EHCP is a web hosting control panel, exploitation could allow attackers to manipulate hosting configurations, access sensitive database information, or pivot to other internal systems. The requirement for authentication limits exposure to insiders or users with valid credentials, but in multi-tenant hosting environments common in Europe, this could still enable lateral movement or targeted attacks against specific clients. The reflected XSS could also be used in phishing campaigns targeting administrators, increasing the risk of credential theft or session hijacking. Given the medium severity and the scope change, confidentiality and integrity impacts are notable, though availability is unaffected. The lack of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once the vulnerability is public. European organizations with web hosting services or managed hosting providers using EHCP are particularly at risk, potentially affecting data privacy compliance under GDPR if personal data is exposed or manipulated.

To mitigate this vulnerability, organizations should implement strict input validation and output encoding on the 'action' parameter within the EHCP 'List MySQL Databases' function. Specifically, applying context-aware encoding (e.g., HTML entity encoding) before reflecting user input in responses is critical. Until an official patch is released, administrators should restrict access to the EHCP interface to trusted networks and users only, employing network segmentation and VPN access controls. Multi-factor authentication (MFA) should be enforced to reduce the risk of compromised credentials. Web Application Firewalls (WAFs) can be configured with custom rules to detect and block suspicious payloads targeting the 'action' parameter. Regular monitoring of logs for unusual parameter values or repeated failed attempts can help detect exploitation attempts. Additionally, educating users about the risks of clicking on untrusted links and implementing Content Security Policy (CSP) headers can reduce the impact of XSS attacks. Organizations should track EHCP vendor advisories for patches and apply updates promptly once available.