CVE-2025-11119 identifies a Cross Site Scripting (XSS) vulnerability in itsourcecode Hostel Management System version 1.0, specifically within the POST request handler of the /justines/index.php file. The vulnerability arises due to insufficient sanitization or encoding of user-supplied input in a parameter named 'results' (exact parameter name unspecified), which allows an attacker to inject arbitrary JavaScript code. This malicious script executes in the context of the victim's browser when they interact with crafted content, enabling attacks such as session hijacking, cookie theft, or redirection to malicious sites. The vulnerability is remotely exploitable without requiring authentication, though user interaction is necessary to trigger the payload. The CVSS v4.0 score of 5.3 reflects a medium severity level, considering the network attack vector, low attack complexity, no privileges required, and user interaction needed. No patches or official fixes have been published yet, and while no active exploits are currently reported in the wild, public exploit code is available, increasing the risk of exploitation. The affected product is niche software used primarily for hostel management, likely deployed in educational or accommodation institutions. The vulnerability does not affect system availability but impacts confidentiality and integrity due to potential data theft or unauthorized actions. The lack of input validation and output encoding in the POST handler is the root cause, and remediation requires secure coding practices to sanitize inputs and encode outputs properly.

For European organizations, particularly educational institutions, hostels, and accommodation providers using the itsourcecode Hostel Management System 1.0, this vulnerability poses a risk to user data confidentiality and system integrity. Successful exploitation could lead to session hijacking, allowing attackers to impersonate legitimate users and access sensitive information or perform unauthorized actions. This can result in data breaches involving personal information of students or guests, damaging organizational reputation and potentially violating GDPR regulations. Although the vulnerability does not directly impact system availability, the indirect consequences of compromised user accounts or stolen credentials could lead to further attacks or data loss. The medium severity rating suggests a moderate risk, but the public availability of exploit code increases the urgency for mitigation. Organizations relying on this software must assess their exposure and implement protective measures promptly to avoid exploitation and comply with European data protection standards.

1. Implement strict input validation on all parameters received via POST requests, especially the 'results' parameter in /justines/index.php, to reject or sanitize any suspicious or script-containing input. 2. Apply proper output encoding (e.g., HTML entity encoding) before rendering user-supplied data in web pages to prevent script execution. 3. Employ Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of potential XSS attacks. 4. Conduct code reviews and security testing focused on input handling and output rendering in the affected component. 5. If possible, isolate or restrict access to the Hostel Management System to trusted networks or VPNs to reduce exposure. 6. Educate users about the risks of clicking on suspicious links or submitting untrusted data. 7. Monitor web application logs for unusual input patterns or error messages indicative of attempted exploitation. 8. Engage with the vendor or community to obtain or develop patches addressing the vulnerability. 9. Consider deploying web application firewalls (WAF) with rules to detect and block XSS payloads targeting the affected endpoint. 10. Regularly update and patch all components once fixes become available to ensure long-term security.