CVE-2021-38347 in Custom Website Data Plugin
Summary
by MITRE • 09/10/2021
The Custom Website Data WordPress plugin is vulnerable to Reflected Cross-Site Scripting via the id parameter found in the ~/views/edit.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 2.2.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 09/16/2021
The CVE-2021-38347 vulnerability affects the Custom Website Data WordPress plugin, specifically targeting versions up to and including 2.2. This represents a critical security flaw that exposes WordPress sites to reflected cross-site scripting attacks, potentially allowing malicious actors to execute arbitrary code within the context of a user's browser. The vulnerability manifests through improper input validation and output encoding mechanisms within the plugin's codebase, creating an avenue for attackers to inject malicious scripts that can persist across user sessions and compromise the integrity of the affected web applications.
The technical flaw resides in the handling of the id parameter within the ~/views/edit.php file, which fails to properly sanitize or escape user-supplied input before rendering it in the web page output. This vulnerability classification aligns with CWE-79, which defines Cross-Site Scripting as a weakness where untrusted data is directly included in dynamic content without proper validation or encoding. The reflected nature of this vulnerability means that the malicious script is reflected off the web server rather than being stored, making it particularly dangerous as it can be delivered through crafted URLs that appear legitimate to users. Attackers can exploit this by constructing malicious URLs with encoded script payloads that get executed when victims click on the links or when their browsers process the reflected content.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable sophisticated attack vectors including session hijacking, credential theft, and data exfiltration. When users navigate to maliciously crafted URLs containing the XSS payload, the injected scripts execute in their browser context, potentially allowing attackers to steal cookies, modify page content, redirect users to malicious sites, or perform actions on behalf of authenticated users. This vulnerability particularly affects WordPress installations where the Custom Website Data plugin is active, creating a persistent threat that can compromise user sessions and potentially escalate to full system compromise if attackers can leverage the executed scripts to gain deeper access to the server infrastructure. The vulnerability also demonstrates poor input validation practices that violate fundamental security principles outlined in the OWASP Top Ten, specifically addressing the importance of proper data sanitization and output encoding in web applications.
Mitigation strategies for CVE-2021-38347 should prioritize immediate plugin updates to versions that address the reflected XSS vulnerability, as this represents the most direct and effective solution. Administrators should also implement comprehensive input validation measures including strict parameter sanitization, output encoding, and Content Security Policy implementations that restrict script execution within the affected application context. Additional defensive measures include monitoring for suspicious URL patterns, implementing web application firewalls that can detect and block malicious script payloads, and conducting regular security audits of installed plugins to ensure all components maintain current security standards. Organizations should also establish robust patch management procedures to ensure timely updates of all WordPress plugins and core components, as this vulnerability demonstrates the critical importance of maintaining current security patches to prevent exploitation of known vulnerabilities. The ATT&CK framework categorizes this as a web application attack vector under the T1059.007 technique for script injection, emphasizing the need for layered security approaches that address both the immediate vulnerability and broader application security posture.