CVE-2021-24136 in Testimonials Widget Plugin
Summary
by MITRE • 03/18/2021
Unvalidated input and lack of output encoding in the Testimonials Widget WordPress plugin, versions before 4.0.0, lead to multiple Cross-Site Scripting vulnerabilities, allowing remote attackers to inject arbitrary JavaScript code or HTML via the below parameters: - Author - Job Title - Location - Company - Email - URL
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Analysis
by VulDB Data Team • 04/02/2021
The CVE-2021-24136 vulnerability represents a critical cross-site scripting flaw in the Testimonials Widget WordPress plugin affecting versions prior to 4.0.0. This vulnerability stems from inadequate input validation and output encoding mechanisms within the plugin's core functionality, creating multiple attack vectors that allow remote code execution through malicious payload injection. The vulnerability specifically targets several user-facing input fields including Author, Job Title, Location, Company, Email, and URL parameters, all of which are susceptible to malicious JavaScript code injection without proper sanitization.
The technical exploitation of this vulnerability aligns with CWE-79, which defines cross-site scripting as a common web application security flaw occurring when applications fail to properly validate or encode user-supplied input before rendering it in web pages. This particular implementation flaw allows attackers to bypass standard security measures by injecting malicious scripts through the testimonial submission forms, which are then executed in the browsers of unsuspecting visitors. The vulnerability operates at the application layer and requires no authentication, making it particularly dangerous as it can be exploited by any remote attacker with knowledge of the target website's structure.
From an operational impact perspective, this vulnerability creates significant risks for WordPress site administrators and users who rely on the Testimonials Widget plugin for customer feedback or company testimonials. When exploited, the malicious JavaScript code can perform various harmful actions including session hijacking, credential theft, redirecting users to malicious websites, or defacing the affected web pages. The attack surface is broad since testimonials are often displayed prominently on websites, increasing the potential exposure to victim users. This vulnerability can be leveraged in conjunction with other attack vectors as part of a broader compromise strategy, potentially enabling persistent threats and data exfiltration.
Mitigation strategies for CVE-2021-24136 should prioritize immediate plugin updates to version 4.0.0 or later, which contain the necessary input validation and output encoding fixes. System administrators should also implement additional security measures including web application firewalls, input sanitization rules, and regular security audits of installed plugins. The remediation process should include thorough testing of the updated plugin to ensure functionality remains intact while addressing the XSS vulnerabilities. Organizations should also consider implementing content security policies and regular security monitoring to detect potential exploitation attempts. According to ATT&CK framework, this vulnerability maps to T1059.001 for command and script injection techniques, emphasizing the need for comprehensive defensive measures across multiple security domains to prevent successful exploitation and maintain overall system integrity.