CVE-2025-13705 in Custom Frames Plugin
Summary
by MITRE • 12/13/2025
The Custom Frames plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'class' parameter of the 'customframe' shortcode in all versions up to, and including, 1.0.1 due to insufficient input sanitization and output escaping. 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 • 12/13/2025
The vulnerability identified as CVE-2025-13705 affects the Custom Frames plugin for WordPress, specifically targeting versions up to and including 1.0.1. This represents a critical security flaw that enables stored cross-site scripting attacks through the 'class' parameter within the 'customframe' shortcode implementation. The issue stems from inadequate input sanitization and insufficient output escaping mechanisms that fail to properly validate or encode user-supplied data before processing.
The technical flaw manifests when authenticated users with Contributor-level privileges or higher submit malicious input through the 'class' parameter of the customframe shortcode. This parameter is processed without proper sanitization measures, allowing attackers to inject malicious JavaScript code that gets stored within the WordPress database. When other users subsequently access pages containing the compromised shortcode, the stored script executes in their browsers, creating a persistent cross-site scripting vulnerability that can be exploited across multiple user sessions.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the ability to perform various malicious activities including session hijacking, credential theft, data exfiltration, and redirection to malicious sites. Since the vulnerability requires only Contributor-level access, it represents a significant risk to WordPress installations where multiple users have varying permission levels, as attackers can leverage this privilege to escalate their access and compromise the entire site. The stored nature of the vulnerability means that the malicious scripts persist even after the initial injection, creating ongoing security risks that can affect all users who view affected pages.
From a cybersecurity perspective, this vulnerability aligns with CWE-79 which describes improper neutralization of input during web page generation, and maps to ATT&CK technique T1566.001 for spearphishing with a malicious attachment or link. The attack vector specifically targets the web application's input validation mechanisms and demonstrates how insufficient sanitization can lead to persistent security weaknesses. Organizations should immediately update to the latest version of the Custom Frames plugin or implement temporary mitigations such as restricting Contributor-level user permissions, implementing web application firewalls, and conducting thorough security audits of all shortcode implementations. Additionally, administrators should monitor for suspicious user activities and ensure proper input validation is implemented across all plugin components to prevent similar vulnerabilities from occurring in other parts of the WordPress ecosystem.