CVE-2025-9710 in Responsive Lightbox & Gallery Plugin
Summary
by MITRE • 10/06/2025
The Responsive Lightbox & Gallery WordPress plugin before 2.5.3 does not properly handle HTML tag attributes modifications, potentially allowing unauthenticated attackers to abuse the functionality to include event handlers and conduct Stored XSS attacks.
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Analysis
by VulDB Data Team • 10/06/2025
The Responsive Lightbox & Gallery WordPress plugin version 2.5.2 and earlier contains a critical security vulnerability that stems from improper handling of HTML tag attributes within its core functionality. This flaw exists in the plugin's processing of user-supplied data that gets rendered in HTML contexts, creating an avenue for malicious actors to inject harmful JavaScript code through stored cross-site scripting attacks. The vulnerability specifically manifests when the plugin fails to adequately sanitize or escape HTML attributes that are modified during the processing of gallery and lightbox elements, allowing attackers to manipulate the output HTML structure.
This security weakness represents a classic stored cross-site scripting vulnerability that aligns with CWE-79, which describes the improper neutralization of input during web page generation. The flaw occurs because the plugin does not properly validate or escape attribute values that are passed through its gallery and lightbox processing functions, enabling attackers to inject malicious JavaScript code into HTML attributes such as onclick, onmouseover, or other event handlers. When legitimate users view pages containing maliciously crafted gallery or lightbox elements, the injected JavaScript executes in their browsers, potentially leading to session hijacking, data theft, or further exploitation of the compromised user environment.
The operational impact of this vulnerability extends beyond simple XSS attacks, as it provides attackers with a persistent vector for executing malicious code against users of compromised WordPress sites. The stored nature of this vulnerability means that once an attacker successfully injects malicious code, it remains active until the malicious content is removed from the site, making it particularly dangerous for websites that allow user-generated content or have multiple administrators with varying levels of access control. This vulnerability can be exploited by unauthenticated attackers, meaning that even users without valid credentials can leverage the flaw to compromise the security of the website and its visitors. The attack surface is particularly concerning given that WordPress plugins are frequently used in content management systems that serve as primary web interfaces for businesses and organizations, making the potential damage from such an attack significant.
Mitigation strategies for this vulnerability should include immediate plugin updates to version 2.5.3 or later, which contains the necessary patches to address the HTML attribute sanitization issues. System administrators should also implement additional security measures such as content security policies that restrict the execution of inline JavaScript and implement proper input validation for all user-supplied content. The vulnerability demonstrates the critical importance of proper HTML escaping and attribute sanitization in web applications, aligning with ATT&CK technique T1059.005 for command and scripting interpreter usage through malicious script injection. Organizations should also consider implementing web application firewalls and regular security audits to detect similar vulnerabilities in other components of their WordPress installations, as this type of flaw often indicates broader issues with input validation and output encoding practices within the application codebase.