CVE-2021-24205 in Elementor Website Builder Plugin
Summary
by MITRE • 04/06/2021
In the Elementor Website Builder WordPress plugin before 3.1.4, the icon box widget (includes/widgets/icon-box.php) accepts a ‘title_size’ parameter. Although the element control lists a fixed set of possible html tags, it is possible for a user with Contributor or above permissions to send a modified ‘save_builder’ request containing JavaScript in the ‘title_size’ parameter, which is not filtered and is output without escaping. This JavaScript will then be executed when the saved page is viewed or previewed.
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Analysis
by VulDB Data Team • 04/10/2021
The vulnerability identified as CVE-2021-24205 affects the Elementor Website Builder WordPress plugin, specifically targeting versions prior to 3.1.4. This security flaw resides within the icon box widget implementation located in includes/widgets/icon-box.php, representing a critical cross-site scripting vulnerability that undermines the plugin's input validation and output sanitization mechanisms. The issue stems from improper handling of user-supplied data within the title_size parameter, which creates an avenue for malicious code execution in contexts where users possess Contributor-level permissions or higher.
The technical flaw manifests through a lack of proper input filtering and output escaping mechanisms within the plugin's widget rendering system. While the element control does define a restricted set of allowable HTML tags for the title_size parameter, the validation process fails to adequately sanitize user input, allowing attackers to inject malicious JavaScript code. This vulnerability operates under CWE-79 which classifies the issue as a Cross-Site Scripting weakness, specifically involving the improper sanitization of user-provided data before its inclusion in web page output. The vulnerability is further categorized under ATT&CK technique T1566.001 which involves phishing with malicious attachments, as the malicious code execution can occur through crafted content that appears legitimate within the WordPress admin interface.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it enables attackers with Contributor privileges or higher to execute arbitrary JavaScript code within the context of the victim's browser. When the compromised page is viewed or previewed, the injected JavaScript executes with the privileges of the logged-in user, potentially leading to session hijacking, data exfiltration, or further privilege escalation within the WordPress environment. The vulnerability affects not only the immediate user but also any other users who may view the compromised page, making it particularly dangerous in collaborative environments where multiple contributors work on the same site. The attack vector requires minimal privileges, as Contributor level access is sufficient to exploit this vulnerability, making it accessible to a wide range of potential attackers.
Mitigation strategies for this vulnerability should focus on immediate plugin updates to version 3.1.4 or later, which contains the necessary patches to address the input sanitization issues. Additionally, administrators should implement proper input validation and output escaping mechanisms throughout the WordPress environment, ensuring that all user-supplied data undergoes rigorous sanitization before being rendered in web pages. The principle of least privilege should be enforced, limiting contributor permissions to prevent unauthorized modifications that could introduce malicious code into the system. Organizations should also consider implementing content security policies and regular security audits to detect and prevent similar vulnerabilities in other components of their WordPress installations. The remediation process should include thorough testing of the updated plugin to ensure that the fix does not introduce compatibility issues with existing site functionality while maintaining the security posture against future exploitation attempts.