CVE-2022-29455: Elementor Website Builder XSS Vulnerability

CVE-2022-29455 Overview

CVE-2022-29455 is a DOM-based Reflected Cross-Site Scripting (XSS) vulnerability affecting the Elementor Website Builder plugin for WordPress in versions 3.5.5 and earlier. Elementor is one of the most widely-used WordPress page builder plugins, powering millions of websites globally. This vulnerability allows unauthenticated attackers to inject malicious scripts into web pages viewed by other users, potentially leading to session hijacking, credential theft, or malware distribution.

Critical Impact

This vulnerability affects over 5 million active WordPress installations using the Elementor plugin, enabling unauthenticated attackers to execute arbitrary JavaScript in victims' browsers through crafted malicious links.

Affected Products

• Elementor Website Builder plugin for WordPress <= 3.5.5
• All WordPress installations running vulnerable Elementor versions
• Sites using Elementor as the primary page builder

Discovery Timeline

• 2022-06-13 - CVE CVE-2022-29455 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-29455

Vulnerability Analysis

This DOM-based Reflected XSS vulnerability (CWE-79) exists in the Elementor Website Builder plugin's client-side JavaScript handling. The vulnerability stems from improper sanitization of user-controlled input that gets reflected into the Document Object Model (DOM) without adequate encoding or validation.

DOM-based XSS attacks differ from traditional reflected XSS because the malicious payload is executed as a result of modifying the DOM environment in the victim's browser rather than being included in the server's HTTP response. In this case, the Elementor plugin processes URL parameters or other user input directly through JavaScript, allowing attackers to craft malicious URLs that, when clicked by victims, execute arbitrary JavaScript code in the context of the affected website.

The network-accessible attack vector requires user interaction (clicking a malicious link), but once triggered, the attacker can execute scripts with the same privileges as the victim user. This could enable session token theft, form data interception, or redirection to malicious sites.

Root Cause

The root cause of CVE-2022-29455 lies in insufficient input validation and output encoding within Elementor's client-side JavaScript code. The plugin fails to properly sanitize user-controlled data before incorporating it into the DOM, allowing script injection through specially crafted URL parameters or input fields.

The vulnerability specifically relates to how Elementor handles dynamic content rendering on the client side. When JavaScript code directly writes user input to the DOM using methods like innerHTML, document.write(), or jQuery's html() function without proper encoding, it creates an opportunity for attackers to inject executable script content.

Attack Vector

The attack leverages the network-accessible entry point to deliver malicious payloads to unsuspecting users. An attacker crafts a URL containing a malicious JavaScript payload as part of a parameter value. When a victim clicks this link while visiting a WordPress site running a vulnerable Elementor version, the malicious script executes in their browser context.

The attack typically involves sending phishing emails or posting malicious links on social media, forums, or comments sections. Since the vulnerability requires no authentication, any visitor to an affected WordPress site can be targeted. The changed scope in the attack means the vulnerability can impact resources beyond just the vulnerable component, potentially affecting other origins or browser contexts.

Successful exploitation could allow attackers to steal session cookies, capture keystrokes, perform actions on behalf of authenticated users, deface web pages, or redirect users to phishing sites. For WordPress administrators, this could lead to complete site compromise if their authenticated session is hijacked.

Detection Methods for CVE-2022-29455

Indicators of Compromise

• Suspicious URL parameters containing encoded JavaScript payloads such as <script>, javascript:, onerror=, or event handlers
• Web server logs showing requests with unusual query string patterns containing HTML entities or URL-encoded script tags
• Browser console errors or unexpected JavaScript execution on Elementor-powered pages
• User reports of unexpected redirects or pop-ups when visiting the WordPress site

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block XSS patterns in URL parameters and request bodies
• Deploy browser-based Content Security Policy (CSP) headers to restrict script execution sources
• Use SentinelOne Singularity Platform to monitor for malicious script injection attempts and anomalous browser behavior
• Regularly audit WordPress plugin versions and compare against known vulnerable versions

Monitoring Recommendations

• Enable comprehensive logging for WordPress and Elementor plugin activities
• Monitor for unusual patterns in web traffic, particularly requests with encoded JavaScript in query strings
• Set up alerts for CSP violation reports which may indicate attempted XSS exploitation
• Utilize SentinelOne's endpoint detection capabilities to identify post-exploitation activities such as credential theft or session hijacking attempts

How to Mitigate CVE-2022-29455

Immediate Actions Required

• Update the Elementor Website Builder plugin to version 3.5.6 or later immediately
• Audit WordPress user accounts for any unauthorized privilege changes or suspicious activity
• Review server access logs for evidence of exploitation attempts using XSS payloads
• Implement Content Security Policy headers to provide defense-in-depth against XSS attacks
• Consider temporarily disabling the Elementor plugin if immediate patching is not possible

Patch Information

The Elementor development team addressed this vulnerability in version 3.5.6 and subsequent releases. WordPress administrators should update to the latest available version of Elementor through the WordPress plugin management interface or by downloading directly from the WordPress Elementor Plugin page.

For detailed vulnerability analysis, refer to the Patchstack Vulnerability Database and Rotem Bar's security research.

Workarounds

• Deploy a Web Application Firewall (WAF) with XSS filtering capabilities to block malicious requests before they reach the application
• Implement strict Content Security Policy headers restricting inline script execution and defining trusted script sources
• Use WordPress security plugins that provide real-time XSS protection and input sanitization
• Limit access to the WordPress admin panel to trusted IP addresses to reduce the impact of potential session hijacking

# Content Security Policy configuration for Apache
# Add to .htaccess file
Header set Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' https://trusted-cdn.example.com; style-src 'self' 'unsafe-inline';"

# For Nginx, add to server block
add_header Content-Security-Policy "default-src 'self'; script-src 'self' https://trusted-cdn.example.com; style-src 'self' 'unsafe-inline';";