CVE-2025-12124 in FitVids Plugin
Summary
by MITRE • 12/05/2025
The FitVids for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in all versions up to, and including, 4.0.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.
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Analysis
by VulDB Data Team • 12/06/2025
The vulnerability identified as CVE-2025-12124 affects the FitVids for WordPress plugin, a popular tool designed to make video embeds responsive across websites. This security flaw represents a critical stored cross-site scripting vulnerability that specifically targets the plugin's admin settings interface. The issue exists in all versions up to and including 4.0.1, making it a widespread concern for WordPress administrators who rely on this plugin for their website's video functionality. The vulnerability is particularly concerning because it requires only administrator-level privileges to exploit, meaning that any attacker who has gained administrative access to a WordPress site can leverage this flaw to persistently inject malicious scripts.
The technical root cause of this vulnerability stems from inadequate input sanitization and insufficient output escaping mechanisms within the plugin's codebase. When administrators configure the plugin settings through the WordPress admin interface, the input data is not properly validated or sanitized before being stored in the database. Additionally, when this data is later retrieved and displayed in the admin interface, the output is not adequately escaped to prevent script execution. This combination of insufficient validation and escaping creates a persistent XSS vector that allows attackers to inject malicious JavaScript code that will execute whenever any user accesses pages containing the injected content. The vulnerability is classified under CWE-79 as a cross-site scripting flaw, specifically manifesting as a stored XSS attack where the malicious payload is permanently stored on the server.
The operational impact of this vulnerability is significant for WordPress installations that utilize the FitVids plugin, particularly in multi-site configurations where the attack surface expands considerably. Attackers who have already compromised administrator credentials can use this vulnerability to establish persistent backdoors, steal session cookies, or redirect users to malicious websites. The attack is particularly effective because it targets the admin settings interface, allowing attackers to inject scripts that will execute whenever administrators access the plugin configuration pages. This creates a stealthy attack vector that can remain undetected for extended periods while maintaining persistent access to the compromised WordPress installation. The vulnerability only affects multi-site installations and installations where unfiltered_html has been disabled, which means that the attack scope is somewhat limited but still represents a serious security risk for affected environments.
Organizations affected by this vulnerability should immediately implement mitigation strategies to protect their WordPress installations. The primary recommendation is to upgrade to the latest version of the FitVids plugin where the XSS vulnerability has been patched. Administrators should also consider implementing additional security measures such as role-based access controls, regular security audits, and monitoring of administrative activities. The vulnerability aligns with several ATT&CK techniques including T1566 for credential harvesting and T1059 for command and scripting interpreter, as attackers can use this vulnerability to execute malicious code and maintain persistence. Security teams should also implement web application firewalls and content security policies to provide additional layers of protection against similar vulnerabilities. Regular patch management processes should be reinforced to ensure timely updates of all WordPress plugins and themes to prevent exploitation of known vulnerabilities.