CVE-2020-36741 in MultiVendorX Plugin
Summary
by MITRE • 07/01/2023
The MultiVendorX plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 3.5.7. This is due to missing or incorrect nonce validation on the submit_comment() function. This makes it possible for unauthenticated attackers to submit comments via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
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Analysis
by VulDB Data Team • 04/10/2026
The MultiVendorX plugin for WordPress presents a critical cross-site request forgery vulnerability identified as CVE-2020-36741 affecting versions up to and including 3.5.7. This vulnerability stems from inadequate security controls within the plugin's comment submission mechanism, specifically in the submit_comment() function where nonce validation is either absent or improperly implemented. The flaw represents a significant risk to WordPress sites utilizing this plugin as it allows unauthenticated attackers to execute malicious actions on behalf of administrators without their knowledge or consent.
The technical nature of this vulnerability places it firmly within the scope of CWE-352, which specifically addresses Cross-Site Request Forgery conditions in web applications. The vulnerability occurs because the plugin fails to properly validate cryptographic nonces that are essential for verifying legitimate user requests. When an administrator visits a malicious website or clicks on a crafted link, the forged request can automatically submit comments to the vulnerable WordPress site through the MultiVendorX plugin interface. This exploitation technique leverages the administrator's authenticated session to perform unauthorized actions, making it particularly dangerous as it bypasses traditional authentication mechanisms.
The operational impact of this vulnerability extends beyond simple comment spamming, as it could potentially enable more sophisticated attacks within the compromised WordPress environment. Attackers could leverage this vulnerability to inject malicious content, manipulate product listings, or even gain further access to the site's administrative functions. The fact that this affects unauthenticated attackers means that no prior access to the WordPress installation is required, making the attack surface significantly broader. This vulnerability particularly impacts e-commerce sites that rely on MultiVendorX for marketplace functionality, as comment manipulation could affect product reviews and customer trust.
Mitigation strategies for CVE-2020-36741 should prioritize immediate plugin updates to versions that properly implement nonce validation. Administrators should also implement additional security measures such as monitoring for unauthorized comment submissions and reviewing plugin access controls. The vulnerability aligns with ATT&CK technique T1071.004, which covers application layer protocol: DNS, as attackers may use this vulnerability to establish persistence or exfiltrate data through manipulated comment systems. Regular security audits of WordPress plugins should include verification of nonce implementation, and administrators should consider implementing web application firewalls to detect and block suspicious comment submission patterns. The vulnerability highlights the critical importance of proper input validation and authentication checks in web application development, particularly for plugins that handle user-generated content in multi-user environments.