CVE-2025-13841 in Smart App Banners Plugin
Summary
by MITRE • 01/07/2026
The Smart App Banners plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'size' and 'verticalalign' parameters of the 'app-store-download' shortcode in all versions up to, and including, 1.2 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 01/07/2026
The Smart App Banners plugin for WordPress presents a critical stored cross-site scripting vulnerability identified as CVE-2025-13841, affecting all versions through 1.2. This vulnerability stems from inadequate input sanitization and output escaping mechanisms within the plugin's 'app-store-download' shortcode implementation. The flaw specifically targets the 'size' and 'verticalalign' parameters, which are processed without proper validation or sanitization of user-supplied input. Attackers with Contributor-level access or higher can exploit this weakness to inject malicious scripts that persist within the plugin's shortcode attributes, making it a stored XSS vulnerability rather than a reflected one. The vulnerability represents a significant security risk as it allows authenticated attackers to execute arbitrary web scripts in the context of affected websites, potentially leading to session hijacking, data theft, or further compromise of the WordPress installation.
The technical exploitation of this vulnerability follows established patterns documented in CWE-79, which classifies cross-site scripting flaws as weaknesses in input validation and output escaping. The plugin's failure to properly sanitize user input before storing it in the database creates a persistent threat vector where malicious code remains embedded in the shortcode attributes. When legitimate users access pages containing the vulnerable shortcode with malicious parameters, their browsers execute the injected scripts, potentially compromising their sessions or enabling attackers to perform actions on their behalf. The vulnerability's impact is amplified by the fact that Contributors and above can modify content, making it accessible to users with relatively low privilege levels within WordPress's role-based access control system. This aligns with ATT&CK technique T1546.001, which covers the use of malicious content to establish persistence and execute code in the context of web applications.
The operational impact of CVE-2025-13841 extends beyond simple script execution, as it provides attackers with potential access to sensitive user data and administrative functions. The stored nature of the vulnerability means that malicious scripts remain active until manually removed from the shortcode parameters, creating a persistent threat that can affect all users who encounter the compromised content. Attackers can leverage this vulnerability to steal cookies, redirect users to malicious sites, or even escalate privileges within the WordPress environment. The vulnerability affects all WordPress installations using the Smart App Banners plugin version 1.2 or earlier, making it particularly concerning for sites with multiple contributors or users who can modify content. Organizations should consider the broader implications for their security posture, as this vulnerability can serve as a foothold for more extensive attacks on the WordPress platform or underlying infrastructure.
Mitigation strategies for CVE-2025-13841 must address both immediate remediation and long-term security improvements. The primary recommendation involves upgrading to the latest version of the Smart App Banners plugin where the vulnerability has been patched, typically through proper input sanitization and output escaping of all user-supplied attributes. Administrators should also implement additional security measures including input validation at multiple layers, regular security audits of plugin installations, and monitoring for unauthorized content modifications. The vulnerability highlights the importance of proper content security policies and input validation practices, as outlined in OWASP's top ten security risks. Organizations should conduct thorough vulnerability assessments to identify any other plugins or themes that may be susceptible to similar issues, particularly those that process user-supplied attributes in shortcodes or other dynamic content generation mechanisms. Regular patch management procedures should be implemented to ensure timely updates of all WordPress components, with particular attention to third-party plugins that may not receive regular security updates from developers.