CVE-2025-48093 is a reflected Cross-site Scripting (XSS) vulnerability identified in the Calvaweb Password only login product, affecting versions up to 0.2. The vulnerability stems from improper neutralization of input during web page generation, allowing attackers to inject malicious JavaScript code into web pages viewed by other users. This type of XSS is 'reflected,' meaning the malicious script is embedded in a URL or input that is immediately reflected back in the HTTP response without proper sanitization. When a victim clicks on a crafted link or submits malicious input, the injected script executes in their browser context, potentially stealing session cookies, redirecting users to phishing sites, or performing unauthorized actions on behalf of the user. The CVSS 3.1 base score of 7.1 reflects a high severity, with attack vector being network-based (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is changed (S:C), indicating the vulnerability affects resources beyond the vulnerable component, and impacts confidentiality, integrity, and availability to a limited degree (C:L/I:L/A:L). No known exploits are reported in the wild yet, but the vulnerability is publicly disclosed and should be considered a significant risk. The affected product is used for password-only login mechanisms, which are common in web applications, increasing the potential attack surface. The lack of available patches at the time of disclosure necessitates immediate mitigation efforts to reduce risk.

For European organizations, this vulnerability poses a significant risk to web applications utilizing the Calvaweb Password only login component. Exploitation can lead to theft of user credentials, session hijacking, and unauthorized actions, potentially compromising sensitive data and disrupting services. This is particularly critical for sectors handling personal data under GDPR, financial institutions, and critical infrastructure providers. The reflected XSS can be leveraged in phishing campaigns targeting employees or customers, increasing the likelihood of successful attacks. The vulnerability’s ability to affect confidentiality, integrity, and availability, combined with the ease of exploitation over the network without authentication, means that organizations face a tangible threat of data breaches and reputational damage. Additionally, the scope change indicates that the impact could extend beyond the immediate vulnerable component, potentially affecting other integrated systems. European organizations that rely on Calvaweb’s authentication solutions should assess their exposure urgently and implement compensating controls to prevent exploitation.

1. Monitor Calvaweb’s official channels for patches addressing CVE-2025-48093 and apply updates promptly once available. 2. Implement strict input validation on all user-supplied data, ensuring that inputs are sanitized and do not contain executable code. 3. Employ robust output encoding/escaping techniques when rendering user input in web pages to prevent script injection. 4. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 5. Use web application firewalls (WAFs) configured to detect and block reflected XSS attack patterns targeting the affected login component. 6. Educate users and employees about the risks of clicking on suspicious links and recognizing phishing attempts that may exploit this vulnerability. 7. Conduct regular security assessments and penetration testing focusing on authentication components to identify and remediate similar issues proactively. 8. Consider implementing multi-factor authentication (MFA) to reduce the impact of credential theft resulting from XSS exploitation.