CVE-2022-1990 in Nested Pages Plugin
Summary
by MITRE • 06/27/2022
The Nested Pages WordPress plugin before 3.1.21 does not escape and sanitize the some of its settings, which could allow high privilege users to perform Stored Cross-Site Scripting attacks when the unfiltered_html is disallowed
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/15/2022
The vulnerability identified as CVE-2022-1990 affects the Nested Pages WordPress plugin version 3.1.20 and earlier, representing a critical stored cross-site scripting weakness that undermines web application security. This flaw exists within the plugin's handling of user settings where insufficient input sanitization and output escaping mechanisms fail to properly process potentially malicious data. The vulnerability specifically impacts scenarios where the WordPress wp-config.php file has the unfiltered_html capability disabled, which is a standard security practice that restricts HTML content in user-generated posts and pages. When this security measure is in place, the vulnerability becomes particularly dangerous as it allows attackers to inject malicious scripts that persist in the application's database and execute whenever affected pages are loaded. The issue stems from the plugin's failure to adequately sanitize user input before storing it in the WordPress database, creating a persistent threat vector that can affect multiple users simultaneously. According to CWE classification, this vulnerability maps to CWE-79 which specifically addresses Cross-Site Scripting flaws in web applications. The ATT&CK framework categorizes this as a code injection technique under the T1566.001 sub-technique, which involves the exploitation of web application vulnerabilities to inject malicious code into web pages viewed by other users.
The technical exploitation of this vulnerability requires an attacker to possess high privilege user accounts within the WordPress environment, typically administrator or editor roles that have access to the Nested Pages plugin settings. The attack vector involves crafting malicious script content within the plugin's configuration parameters, which are then stored in the database without proper sanitization. When other users access pages managed by the Nested Pages plugin, their browsers execute the stored malicious scripts, potentially leading to session hijacking, credential theft, or further compromise of the affected WordPress installation. The vulnerability's persistence stems from the fact that stored XSS attacks maintain their malicious payloads in the application's database rather than relying on transient input methods. This characteristic makes the attack more insidious and harder to detect, as the malicious code remains active until manually removed or until the vulnerable plugin is updated. The lack of proper escaping mechanisms means that HTML and script characters are not converted into harmless text representations before being stored, allowing attackers to embed JavaScript code that executes in the context of other users' browsers.
The operational impact of CVE-2022-1990 extends beyond simple script execution, potentially enabling attackers to gain unauthorized access to sensitive user data and administrative functions within the WordPress environment. When high privilege users are compromised, attackers can manipulate content, modify user permissions, or even exfiltrate database information through the executed malicious scripts. The vulnerability's exploitation can lead to complete compromise of the WordPress site, especially when combined with other security misconfigurations or additional vulnerabilities within the broader application stack. Organizations using the affected plugin version face significant risk of data breaches, as the stored XSS attack can be used to steal cookies, session tokens, or other sensitive information that allows attackers to impersonate legitimate users. The vulnerability also affects the integrity of the website content, as attackers can modify or replace existing pages with malicious content, potentially spreading the attack to visitors. Security monitoring becomes challenging because the malicious scripts are stored within legitimate application components, making them difficult to distinguish from normal application behavior. The impact is particularly severe in multi-user environments where administrators may unknowingly introduce malicious payloads that affect numerous site visitors.
Mitigation strategies for CVE-2022-1990 require immediate action to update the Nested Pages plugin to version 3.1.21 or later, which contains the necessary patches to address the sanitization and escaping vulnerabilities. Organizations should also implement comprehensive input validation and output escaping mechanisms throughout their WordPress installations, ensuring that all user-provided data is properly sanitized before being stored or displayed. Security administrators should review and tighten WordPress user role permissions, limiting access to plugin settings to only essential personnel who require such capabilities for legitimate administrative purposes. The implementation of Content Security Policy headers can provide additional protection against script execution, even if the underlying vulnerability is not immediately patched. Regular security audits of WordPress plugins and themes should include verification of proper input sanitization and output escaping practices, as specified in the OWASP Top Ten security standards. Organizations should also consider implementing Web Application Firewalls to detect and block malicious script injection attempts. Monitoring for suspicious plugin activity and regular database scans can help identify compromised entries before they can be exploited. The vulnerability demonstrates the critical importance of proper security practices in WordPress plugin development, particularly regarding input validation and output escaping, as outlined in the WordPress Plugin Developer Handbook security guidelines. System administrators should also maintain regular backups of their WordPress installations to ensure rapid recovery in case of successful exploitation attempts.