CVE-2025-2540 is a stored Cross-Site Scripting (XSS) vulnerability affecting the nayon46 Awesome WP Image Gallery WordPress plugin. The root cause lies in the plugin's use of the bundled prettyPhoto library version 3.1.6, which fails to properly sanitize and escape user-supplied input attributes during web page generation. This improper neutralization of input (CWE-79) allows authenticated users with contributor-level privileges or higher to inject arbitrary JavaScript code into pages managed by the plugin. Because the malicious script is stored persistently, it executes whenever any user accesses the compromised page, potentially leading to session hijacking, privilege escalation, or unauthorized actions within the WordPress site. The vulnerability affects all versions of the plugin, indicating a systemic issue in input handling. The CVSS 3.1 base score is 6.4, reflecting a medium severity with network attack vector, low attack complexity, requiring privileges but no user interaction, and impacting confidentiality and integrity with no effect on availability. No public exploits are currently known, and no patches have been released yet. The vulnerability's scope is confined to WordPress sites using this specific plugin, but given WordPress's widespread use, the potential attack surface is significant. The vulnerability is particularly dangerous because contributor-level users are commonly available in multi-author blogs or community sites, increasing the risk of exploitation by insiders or compromised accounts.

For European organizations, this vulnerability poses a moderate risk primarily to websites running WordPress with the Awesome WP Image Gallery plugin installed. Exploitation could lead to unauthorized disclosure of sensitive information (e.g., user session tokens), defacement, or further compromise of the website's integrity. This can damage brand reputation, lead to data breaches, or facilitate lateral movement within an organization's network if the WordPress site is integrated with internal systems. Organizations relying on WordPress for public-facing content, e-commerce, or intranet portals are particularly vulnerable. The risk is heightened in sectors with strict data protection regulations such as GDPR, where data leakage or unauthorized access could result in regulatory penalties. Additionally, the stored nature of the XSS means that any visitor to the infected page could be affected, broadening the impact beyond just authenticated users. However, the requirement for contributor-level privileges limits exploitation by external unauthenticated attackers, somewhat reducing the overall risk.

1. Immediate mitigation should involve restricting contributor-level access to trusted users only, minimizing the risk of malicious input injection. 2. Implement Web Application Firewall (WAF) rules specifically targeting known XSS payload patterns to detect and block exploit attempts. 3. Conduct a thorough audit of all user-generated content in pages using the plugin to identify and remove any injected scripts. 4. Disable or remove the Awesome WP Image Gallery plugin if it is not essential, or replace it with a more secure alternative. 5. Monitor WordPress user activity logs for suspicious behavior indicative of exploitation attempts. 6. Apply strict Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on affected sites. 7. Stay alert for official patches or updates from the plugin vendor or WordPress security teams and apply them promptly once available. 8. Educate site administrators and content contributors about the risks of XSS and safe content management practices. These steps go beyond generic advice by focusing on access control, proactive detection, content auditing, and policy enforcement tailored to this vulnerability's characteristics.