CVE-2015-9532 in Digital Store Theme
Summary
by MITRE
The Easy Digital Downloads (EDD) Digital Store theme for WordPress, as used with EDD 1.8.x before 1.8.7, 1.9.x before 1.9.10, 2.0.x before 2.0.5, 2.1.x before 2.1.11, 2.2.x before 2.2.9, and 2.3.x before 2.3.7, has XSS because add_query_arg is misused.
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Analysis
by VulDB Data Team • 02/07/2025
The vulnerability CVE-2015-9532 represents a cross-site scripting flaw discovered in the Easy Digital Downloads WordPress theme, which affected multiple versions of the EDD plugin ecosystem. This security weakness stems from improper implementation of the add_query_arg function within the theme's codebase, creating a vector for malicious attackers to inject arbitrary JavaScript code into web pages viewed by unsuspecting users. The affected versions spanned across several major release branches including 1.8.x through 2.3.x, indicating a widespread issue that impacted a significant portion of WordPress users utilizing this popular digital storefront solution. The vulnerability specifically manifests when user-supplied input is not properly sanitized before being processed through the add_query_arg function, which is designed to handle query parameters in URLs.
The technical exploitation of this vulnerability occurs through manipulation of URL parameters that are then passed through the add_query_arg function without adequate validation or escaping mechanisms. When legitimate users navigate to pages containing maliciously crafted URLs, the improperly handled query parameters get embedded directly into the HTML output, allowing attackers to execute malicious scripts in the context of other users' browsers. This misimplementation creates a persistent XSS vector that can be leveraged for session hijacking, credential theft, or redirection to malicious websites. The flaw aligns with CWE-79, which specifically addresses Cross-Site Scripting vulnerabilities, and demonstrates how improper input validation and output encoding can lead to severe security consequences. Attackers can craft URLs with malicious payloads that, when clicked by victims, execute code in their browsers and potentially compromise the entire user session.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform sophisticated attacks such as cookie theft, defacement of user accounts, or redirection to phishing sites that mimic legitimate EDD interfaces. Users who are logged into their WordPress admin panels or EDD stores become particularly vulnerable, as the injected scripts can potentially escalate privileges or access sensitive administrative functions. The widespread nature of the affected versions means that countless WordPress sites utilizing EDD were exposed to this risk, creating a substantial attack surface for threat actors. Organizations using this theme could experience reputational damage, loss of customer trust, and potential data breaches. The vulnerability also demonstrates how seemingly benign functions like add_query_arg can become security risks when not properly integrated with input validation and output sanitization practices, highlighting the importance of secure coding practices in web application development.
Mitigation strategies for this vulnerability require immediate patching of affected EDD versions to the latest available releases, which include proper sanitization of query parameters and implementation of appropriate output escaping mechanisms. System administrators should conduct comprehensive vulnerability assessments to identify any instances of the affected theme versions and ensure all installations are updated to patched versions. Additionally, implementing Content Security Policy headers can provide an additional layer of protection against XSS attacks by restricting script execution sources. Regular security audits and input validation testing should be integrated into the development lifecycle to prevent similar issues from arising in future implementations. The vulnerability also underscores the necessity of following OWASP Top Ten security guidelines and implementing proper secure coding practices that include parameter validation, output encoding, and proper error handling to prevent injection vulnerabilities in web applications.