CVE-2018-19906 is a stored Cross-Site Scripting (XSS) vulnerability identified in razorCMS version 3.4.8. The vulnerability arises from improper sanitization of user input in the 'description' parameter of the /#/page endpoint. Stored XSS vulnerabilities occur when malicious scripts injected by an attacker are permanently stored on the target server and subsequently executed in the browsers of users who access the affected page. In this case, an attacker can craft a payload that, when submitted via the vulnerable parameter, is saved and later rendered without proper encoding or sanitization, leading to script execution in the context of the victim's browser. The CVSS v3.1 base score for this vulnerability is 5.4, indicating a medium severity level. The vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N) shows that the attack can be performed remotely over the network (AV:N) with low attack complexity (AC:L), but requires some level of privileges (PR:L) and user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact affects confidentiality and integrity to a low degree (C:L/I:L) but does not affect availability (A:N). Stored XSS can lead to session hijacking, defacement, phishing, or unauthorized actions performed on behalf of the user. Although no known exploits in the wild have been reported, the presence of this vulnerability in razorCMS 3.4.8 poses a risk to websites using this CMS, especially if they allow authenticated users to submit content that is displayed to others. No official patches or vendor advisories are linked, which may require users to implement custom mitigations or upgrade to a fixed version if available.

For European organizations using razorCMS 3.4.8, this vulnerability could lead to compromise of user sessions, theft of sensitive information, or unauthorized actions performed via malicious scripts injected into the CMS pages. This is particularly concerning for organizations that rely on razorCMS for public-facing websites or intranet portals where multiple users interact. The confidentiality and integrity of user data could be undermined, potentially leading to reputational damage, regulatory non-compliance (e.g., GDPR violations if personal data is exposed), and financial losses. Since the vulnerability requires authenticated access and user interaction, the risk is somewhat mitigated but remains significant in environments with many users or where social engineering could be employed to trigger the exploit. Given the medium severity and the changed scope, attackers could leverage this vulnerability to pivot within the affected environment, potentially escalating attacks or targeting high-value users. The lack of known exploits suggests limited active exploitation, but the vulnerability remains a latent risk if not addressed.

1. Upgrade razorCMS to the latest version if a patch addressing CVE-2018-19906 is available. If no official patch exists, consider applying community or custom fixes that sanitize and encode the 'description' parameter input properly. 2. Implement strict input validation and output encoding on all user-supplied content, especially in parameters that are rendered in HTML contexts. Use well-established libraries or frameworks for sanitization to prevent injection of malicious scripts. 3. Restrict privileges for users who can submit or edit page descriptions to minimize the risk of malicious input. Employ the principle of least privilege. 4. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers, reducing the impact of potential XSS payloads. 5. Conduct regular security audits and penetration testing focusing on input handling and stored XSS vulnerabilities. 6. Educate users about the risks of interacting with suspicious links or content that could trigger stored XSS attacks. 7. Monitor web server logs and application behavior for unusual activity that might indicate exploitation attempts. 8. If feasible, isolate razorCMS installations in segmented network zones to limit lateral movement in case of compromise.