CVE-2023-23701 in Andrew @ Geeenville Web Design Easy Sign Up Plugin
Summary
by MITRE • 05/10/2023
Auth. (contributor+) Stored Cross-Site Scripting (XSS) vulnerability in Andrew @ Geeenville Web Design Easy Sign Up plugin <= 3.4.1 versions.
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Analysis
by VulDB Data Team • 06/07/2023
The CVE-2023-23701 vulnerability represents a stored cross-site scripting flaw within the Easy Sign Up plugin for WordPress, specifically affecting versions up to and including 3.4.1. This vulnerability falls under the category of authentication-related security issues where unauthenticated or low-privilege users can potentially exploit the flaw to execute malicious scripts in the context of other users' browsers. The vulnerability is particularly concerning because it affects contributor-level users and above, meaning that attackers with these privileges can inject malicious code that persists in the application's database and executes whenever affected pages are loaded.
The technical implementation of this vulnerability stems from insufficient input validation and output escaping within the plugin's handling of user-submitted data. When contributors or higher-level users submit content through the plugin's interface, the application fails to properly sanitize or encode the input before storing it in the database. This stored data is then retrieved and displayed without adequate security measures to prevent script execution. The flaw is classified as a stored XSS vulnerability according to CWE-79, which specifically addresses cross-site scripting where malicious scripts are stored on the server and executed when other users access the affected content. The vulnerability is further characterized by its authentication requirements, as it only affects users with contributor permissions or higher, making it a privilege escalation vector rather than a fully open exploit.
The operational impact of this vulnerability extends beyond simple script execution as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and data exfiltration. An attacker with contributor access can inject JavaScript code that executes in the context of other users' browsers, potentially allowing them to steal session cookies, redirect users to malicious sites, or manipulate the application's functionality. The stored nature of the vulnerability means that the malicious payload persists even after the initial injection, making it particularly dangerous as it can affect multiple users over extended periods. This type of vulnerability can also facilitate more sophisticated attacks such as credential harvesting through keylogging scripts or browser manipulation techniques that align with ATT&CK tactics including T1566 (Phishing) and T1071.001 (Application Layer Protocol: Web Protocols) when combined with social engineering elements.
Mitigation strategies for CVE-2023-23701 should prioritize immediate plugin updates to versions that address the stored XSS vulnerability, as this represents the most direct and effective solution. Organizations should also implement additional security measures including input validation at multiple layers, output encoding for all user-generated content, and regular security auditing of WordPress plugins to identify similar vulnerabilities. The implementation of Content Security Policy headers can provide an additional defense-in-depth mechanism to prevent script execution even if other security measures fail. Regular security monitoring and user access reviews should be conducted to ensure that only authorized individuals have contributor-level permissions, as this vulnerability specifically requires at least contributor privileges to exploit. Furthermore, maintaining up-to-date security patches for the WordPress core and all plugins demonstrates adherence to industry best practices and helps prevent similar vulnerabilities from being exploited in the broader WordPress ecosystem.