CVE-2024-5342 is a stored cross-site scripting vulnerability identified in the Simple Image Popup Shortcode plugin for WordPress, maintained by purvabathe. The flaw exists in all versions up to and including 1.0 due to insufficient sanitization and escaping of user input passed through the 'sips_popup' shortcode attributes. This allows authenticated users with contributor-level access or higher to inject arbitrary JavaScript code into pages or posts. When other users, including administrators or visitors, access these pages, the malicious scripts execute in their browsers, potentially leading to session hijacking, privilege escalation, or defacement. The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation). Exploitation requires authentication but no user interaction beyond viewing the infected page. The CVSS 3.1 score is 6.4, reflecting network attack vector, low attack complexity, privileges required, no user interaction, and partial confidentiality and integrity impact. No patches or official fixes have been published yet, and no known exploits are reported in the wild. The vulnerability affects all versions of the plugin, which is used in WordPress environments, a widely deployed content management system globally. The issue highlights the importance of rigorous input validation and output encoding in WordPress plugins to prevent persistent XSS attacks.

The primary impact of CVE-2024-5342 is the potential for attackers with contributor-level access to inject persistent malicious scripts into WordPress sites using the vulnerable plugin. This can lead to session hijacking, theft of sensitive user information, defacement of website content, or redirection to malicious sites. Since the injected scripts execute in the context of the affected website, they can bypass same-origin policies and compromise the confidentiality and integrity of user sessions. Organizations relying on this plugin risk reputational damage, loss of user trust, and potential regulatory consequences if user data is compromised. The vulnerability does not directly affect availability but can indirectly cause service disruptions if exploited for defacement or malware distribution. The requirement for authenticated access limits the attack surface but does not eliminate risk, especially on sites with multiple contributors or less stringent access controls. Given WordPress's global popularity, the vulnerability could affect a broad range of organizations, from small blogs to large enterprises using this plugin.

Organizations should immediately audit their WordPress installations to identify the presence of the Simple Image Popup Shortcode plugin. If found, restrict contributor-level and higher privileges to trusted users only until a patch is available. Employ Web Application Firewalls (WAFs) with custom rules to detect and block malicious payloads targeting the 'sips_popup' shortcode attributes. Implement strict input validation and output encoding in custom plugin code or consider disabling the vulnerable shortcode if feasible. Monitor site content for unauthorized script injections and review user activity logs for suspicious behavior. Encourage plugin developers or maintainers to release a security update addressing the input sanitization and output escaping issues. In the interim, consider replacing the plugin with alternative solutions that follow secure coding practices. Regularly update WordPress core and plugins to minimize exposure to known vulnerabilities. Educate contributors about the risks of injecting untrusted content and enforce the principle of least privilege.