CVE-2021-25974 is a stored Cross-site Scripting (XSS) vulnerability identified in the Publify Core content management system, specifically affecting versions from v8.0 up to v9.2.4. The vulnerability arises because a user with the "publisher" role can inject arbitrary JavaScript code into pages or articles they create. This malicious script is then stored persistently on the server and executed in the browsers of users who view the affected content. The vulnerability is classified under CWE-79, which pertains to improper neutralization of input leading to XSS attacks. The CVSS v3.1 base score 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) reveals that the attack can be performed remotely over the network (AV:N) with low attack complexity (AC:L), but requires the attacker to have privileges equivalent to a publisher role (PR:L) and requires user interaction (UI:R) to trigger the malicious script. The scope is changed (S:C), meaning the vulnerability affects components beyond the initially vulnerable component. The impact affects confidentiality and integrity to a limited extent (C:L, I:L) but does not affect availability (A:N). No known exploits have been reported in the wild, and no official patches are linked in the provided data, though the vulnerability has been publicly disclosed since November 2021. The vulnerability allows attackers to execute arbitrary JavaScript in the context of the victim’s browser, potentially enabling session hijacking, defacement, or redirection to malicious sites, depending on the victim's privileges and the environment.

For European organizations using Publify Core versions 8.0 through 9.2.4, this vulnerability poses a moderate risk. Since the attack requires a user with publisher-level privileges to inject malicious scripts, the threat is primarily insider or compromised account driven. However, once exploited, the stored XSS can affect any user viewing the compromised content, potentially leading to credential theft, unauthorized actions, or spreading malware within the organization. This can impact confidentiality by exposing session tokens or sensitive data, and integrity by altering displayed content or injecting malicious payloads. The vulnerability does not directly impact system availability but can undermine trust in the affected web platform. European organizations in sectors relying on Publify Core for content management, such as media, publishing, education, or government websites, could face reputational damage and regulatory scrutiny under GDPR if personal data is compromised. The cross-site scripting nature also raises concerns about phishing and social engineering attacks leveraging the trusted domain. Given the scope change in the CVSS vector, the vulnerability could affect multiple components or user roles beyond the initial publisher context, increasing the potential attack surface.

1. Immediate upgrade: Organizations should upgrade Publify Core to the latest version beyond 9.2.4 where this vulnerability is patched. If an upgrade is not immediately possible, apply any available vendor-supplied patches or mitigations. 2. Role auditing and restriction: Review and limit the assignment of the publisher role strictly to trusted users. Implement the principle of least privilege to reduce the risk of malicious content injection. 3. Input sanitization and output encoding: Implement additional server-side input validation and output encoding to neutralize any injected scripts, especially in user-generated content. 4. Content Security Policy (CSP): Deploy a strict CSP header to restrict the execution of unauthorized scripts and reduce the impact of any injected code. 5. User awareness and monitoring: Educate users about the risks of XSS and monitor logs for unusual content creation or modification activity by publisher-role users. 6. Web Application Firewall (WAF): Configure a WAF with rules to detect and block typical XSS payloads targeting Publify Core. 7. Incident response readiness: Prepare to respond to potential exploitation by having processes to quickly identify and remediate injected malicious content and notify affected users if needed.