CVE-2015-9505 in Easy Digital Downloads
Summary
by MITRE
The Easy Digital Downloads (EDD) core component 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 for WordPress has XSS because add_query_arg is misused.
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Analysis
by VulDB Data Team • 02/08/2025
The Easy Digital Downloads plugin for WordPress represents a widely deployed e-commerce solution that enables website administrators to sell digital products and services directly from their WordPress sites. This plugin serves as a core component for numerous websites handling financial transactions and customer data, making its security paramount to overall site integrity. The vulnerability identified in versions prior to the specified patches affects the plugin's core functionality, specifically within its handling of URL parameters and query arguments. The flaw manifests in how the plugin processes user-supplied data through the add_query_arg function, creating a pathway for malicious actors to inject harmful scripts into the application's response.
The technical implementation of this cross-site scripting vulnerability stems from improper sanitization of query parameters within the plugin's core processing logic. When the add_query_arg function receives user input without adequate validation or encoding, it allows malicious payloads to be embedded directly into URLs that are subsequently rendered in web pages. This misconfiguration enables attackers to inject script code that executes in the context of other users' browsers when they visit pages containing the maliciously crafted URLs. The vulnerability exists across multiple version lines of the plugin, indicating a persistent flaw in the codebase's approach to parameter handling and security validation.
The operational impact of this vulnerability extends beyond simple script injection, potentially enabling attackers to perform a range of malicious activities including session hijacking, credential theft, and data manipulation. An attacker could craft URLs that, when visited by administrators or other users, would execute malicious scripts that could steal cookies, redirect users to phishing sites, or even modify site content. The widespread adoption of Easy Digital Downloads means that numerous WordPress sites could be compromised simultaneously, creating a significant risk for businesses relying on the plugin for their online sales operations. The vulnerability's presence across multiple version branches suggests that the underlying security flaw was not properly addressed during development cycles, leaving users exposed for extended periods.
Mitigation strategies should prioritize immediate patching of affected versions to the latest stable releases that contain the necessary security fixes. System administrators must conduct thorough inventory assessments to identify all installations of the vulnerable plugin versions and implement comprehensive testing procedures before applying updates. Security monitoring should include detection of suspicious URL patterns and query parameters that might indicate exploitation attempts. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws, and demonstrates characteristics consistent with ATT&CK technique T1566 related to credential access through phishing. Organizations should also implement input validation and output encoding measures to prevent similar issues in other parts of their web applications, establishing defense-in-depth strategies that protect against both known and emerging threats in the WordPress ecosystem.