CVE-2023-5337 in Contact Form Form for All Plugin
Summary
by MITRE • 10/25/2023
The Contact form Form For All plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'formforall' shortcode in versions up to, and including, 1.2 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions 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 • 04/10/2026
The vulnerability identified as CVE-2023-5337 affects the Form For All WordPress plugin, specifically versions up to and including 1.2, where a stored cross-site scripting flaw exists within the formforall shortcode implementation. This security weakness stems from inadequate input sanitization and output escaping mechanisms that fail to properly validate or sanitize user-supplied attributes before processing them within the plugin's shortcode functionality. The vulnerability is particularly concerning because it allows authenticated attackers who possess contributor-level permissions or higher to execute malicious scripts within the context of affected websites. The stored nature of this XSS vulnerability means that malicious payloads injected through the formforall shortcode are permanently saved within the WordPress database, making them persistent threats that will execute every time affected pages are accessed by any user with appropriate privileges.
The technical flaw manifests when the plugin processes user input through the formforall shortcode attributes without implementing proper sanitization filters or output escaping mechanisms. This creates an environment where malicious actors can inject JavaScript code or other malicious payloads that will execute whenever legitimate users access pages containing the vulnerable shortcode. The vulnerability's impact extends beyond simple script execution as it provides attackers with the ability to perform various malicious activities including session hijacking, data exfiltration, and privilege escalation within the WordPress environment. According to CWE classification, this represents a CWE-79: Cross-Site Scripting vulnerability, specifically manifesting as a stored XSS attack pattern that allows persistent malicious code execution. The ATT&CK framework categorizes this as a technique involving code injection and privilege escalation through web application vulnerabilities, with the attacker leveraging their contributor-level access to establish persistent malicious presence within the target environment.
The operational impact of CVE-2023-5337 is significant for WordPress sites utilizing the vulnerable plugin, as it creates a persistent backdoor for attackers to maintain access and execute malicious activities over extended periods. Once exploited, the vulnerability allows attackers to potentially steal user credentials, manipulate content, or redirect users to malicious sites, making it particularly dangerous for websites that host sensitive information or have multiple user roles. The requirement for only contributor-level permissions to exploit this vulnerability means that even relatively low-privilege accounts can become attack vectors, increasing the potential attack surface for compromised WordPress installations. Organizations using this plugin should immediately implement mitigation strategies including plugin updates, input validation hardening, and monitoring for suspicious shortcode usage patterns. The vulnerability demonstrates the critical importance of proper input sanitization and output escaping practices in web application development, particularly for plugins that handle user-generated content through shortcode mechanisms. Security teams must also consider implementing web application firewalls and content security policies to provide additional defense layers against similar vulnerabilities in other components of their WordPress infrastructure.