CVE-2020-36711 in Avada Theme
Summary
by MITRE • 06/07/2023
The Avada theme for WordPress is vulnerable to Stored Cross-Site Scripting via the update_layout function in versions up to, and including, 6.2.3 due to insufficient input sanitization and output escaping. This makes it possible for contributor-level attackers, and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 07/05/2023
The Avada theme for WordPress represents one of the most widely used premium themes in the wordpress ecosystem with over 100000 installations as of 2020. This vulnerability affects versions up to and including 6.2.3 which demonstrates a critical oversight in the theme's security implementation. The stored cross-site scripting vulnerability specifically targets the update_layout function which serves as a core component in the theme's layout management system. This flaw exists because the developers failed to implement proper input sanitization measures and output escaping mechanisms within the affected function. The vulnerability's impact is particularly severe given that it requires only contributor-level user privileges to exploit, making it accessible to users who typically have limited administrative capabilities within wordpress environments.
The technical exploitation of this vulnerability occurs through the update_layout function which processes user input without adequate sanitization before storing it in the database. When malicious scripts are injected through this pathway, they become permanently stored within the wordpress content management system. Any user who accesses pages containing these stored scripts will execute the malicious code within their browser context, creating a persistent threat vector. The vulnerability operates at the application layer and specifically targets the theme's rendering engine where user-provided data is processed and displayed. This type of stored xss attack falls under the category of CWE-79 which defines improper neutralization of input during web output. The attack chain begins with an authenticated user submitting malicious content through the update_layout function, followed by the stored data being retrieved and executed during normal page rendering operations.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with the capability to perform various malicious activities including session hijacking, credential theft, and data exfiltration. Contributors and above can leverage this vulnerability to compromise other users within the same wordpress installation, potentially leading to full system compromise if additional vulnerabilities exist. The stored nature of the exploit means that the malicious code persists even after the initial injection, creating a long-term threat that can affect multiple users over extended periods. This vulnerability particularly impacts organizations that rely on wordpress for content management where user roles are not properly restricted or monitored. The attack surface is further expanded when considering that many wordpress installations lack proper security monitoring or intrusion detection systems to identify such stored payloads.
Mitigation strategies for this vulnerability should include immediate patching to version 6.2.4 or later which contains the necessary input sanitization and output escaping fixes. Organizations should also implement role-based access controls to minimize the potential impact of compromised contributor accounts through additional security measures such as two-factor authentication and restricted user permissions. The implementation of content security policies can provide additional defense in depth measures to prevent execution of unauthorized scripts even if the underlying vulnerability is not patched immediately. Security monitoring should include regular content audits and automated scanning for suspicious script injections within wordpress databases. From a compliance perspective, this vulnerability aligns with security standards such as those outlined in the owasp top ten project where xss vulnerabilities consistently rank among the most critical web application security risks. The attack pattern demonstrates characteristics consistent with the att&ck framework's credential access and execution techniques, particularly the use of web shell and script injection methods to establish persistent access to target systems.