CVE-2021-4390 in Contact Form 7 Style Plugin
Summary
by MITRE • 07/01/2023
The Contact Form 7 Style plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 3.2. This is due to missing or incorrect nonce validation on the manage_wp_posts_be_qe_save_post() function. This makes it possible for unauthenticated attackers to quick edit templates 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 • 07/01/2023
The Contact Form 7 Style plugin for WordPress represents a widely used tool for customizing contact form appearances within wordpress environments. This particular plugin version 3.2 and earlier contains a critical cross-site request forgery vulnerability that compromises the security integrity of wordpress installations. The vulnerability stems from inadequate security controls within the plugin's administrative interface, specifically targeting the manage_wp_posts_be_qe_save_post() function which handles template modifications. The absence of proper nonce validation creates an exploitable condition that allows malicious actors to manipulate form templates without authentication.
Cross-site request forgery vulnerabilities fall under the CWE-352 category, which specifically addresses the lack of proper validation of requests originating from authenticated users. This vulnerability operates by tricking authenticated administrators into executing unintended actions through maliciously crafted requests. The attack vector requires social engineering elements where attackers must convince administrators to click on malicious links or visit compromised websites that trigger the forged requests. The vulnerability is particularly dangerous because it allows attackers to modify critical template files that control how contact forms appear and function on the website.
The operational impact of this vulnerability extends beyond simple template manipulation to potentially compromise entire website functionalities. When an administrator performs the forged request, the attacker can modify form configurations, alter field placements, or even inject malicious code into template files. This creates opportunities for data exfiltration, phishing attacks, or further exploitation of the compromised wordpress installation. The vulnerability affects all administrators with sufficient privileges to edit contact form templates, making it particularly concerning for sites with multiple administrators or less security-conscious users.
Security mitigations for this vulnerability require immediate plugin updates to versions that implement proper nonce validation controls. WordPress administrators should ensure their Contact Form 7 Style plugin is updated to the latest version that addresses this specific CSRF flaw. Additionally, implementing additional security measures such as role-based access controls, regular security audits, and monitoring for unauthorized template modifications can help detect and prevent exploitation attempts. Organizations should also consider implementing web application firewalls and security headers to provide additional layers of protection against similar CSRF attacks. The ATT&CK framework categorizes this vulnerability under initial access and privilege escalation techniques, emphasizing the importance of maintaining proper authentication controls and validating all user requests. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues across all installed plugins and themes.