CVE-2023-46210 in WC Captcha Plugin
Summary
by MITRE • 10/31/2023
Auth. (admin+) Stored Cross-Site Scripting (XSS) vulnerability in WebCource WC Captcha plugin <= 1.4 versions.
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Analysis
by VulDB Data Team • 11/24/2023
The CVE-2023-46210 vulnerability represents a critical stored cross-site scripting flaw within the WebCource WC Captcha plugin for WordPress, affecting versions 1.4 and earlier. This vulnerability specifically targets administrative users with privileges equal to or greater than administrator level, making it particularly dangerous as it allows attackers to execute malicious scripts within the context of authenticated admin sessions. The flaw resides in how the plugin processes and stores user input without proper sanitization or validation, creating a persistent XSS vector that can be exploited by malicious actors with administrative access or those capable of obtaining such privileges.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding within the plugin's captcha handling mechanisms. When administrators interact with the plugin's administrative interface or when user-submitted data is processed through the captcha system, the plugin fails to properly sanitize malicious payloads before storing them in the database. This stored data is then subsequently rendered in administrative contexts without appropriate HTML escaping or context-aware output encoding, allowing attackers to inject malicious JavaScript code that executes whenever administrators view affected pages. The vulnerability operates as a classic stored XSS attack where the malicious script is permanently stored on the server and executed every time the vulnerable page is accessed by an authenticated user.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the ability to fully compromise administrative sessions and potentially gain complete control over the WordPress installation. An attacker with administrator privileges could leverage this vulnerability to modify or delete content, install malicious plugins, alter user permissions, or even exfiltrate sensitive data from the WordPress environment. The persistent nature of stored XSS means that the malicious code remains active until manually removed from the database, allowing for extended periods of unauthorized access and potential data exfiltration. This vulnerability directly aligns with CWE-79 which defines cross-site scripting as a common web application security flaw where untrusted data is improperly incorporated into web pages served to users.
Mitigation strategies for CVE-2023-46210 should prioritize immediate plugin updates to versions 1.5 or later where the vulnerability has been patched through proper input validation and output encoding mechanisms. Organizations should implement comprehensive monitoring of administrative user activities and conduct regular security audits of installed plugins to identify potentially vulnerable components. Network-based intrusion detection systems should be configured to monitor for suspicious script injection patterns in administrative interfaces, while security headers such as Content-Security-Policy should be implemented to provide additional protection layers against XSS exploitation attempts. The vulnerability demonstrates the importance of proper input sanitization and output encoding practices as outlined in the OWASP Top Ten and aligns with ATT&CK technique T1059.001 for command and script injection, highlighting the need for robust application security controls throughout the software development lifecycle.