CVE-2025-6740 identifies a stored Cross-Site Scripting (XSS) vulnerability in the Contact Form 7 Database Addon (CFDB7) plugin for WordPress, maintained by arshidkv12. This vulnerability exists in all versions up to and including 1.3.1 due to insufficient sanitization and escaping of the ‘tmpD’ parameter during web page generation. An unauthenticated attacker can exploit this flaw by injecting arbitrary JavaScript code into the plugin’s stored data, which is then rendered and executed in the browser of any user who views the affected page. This stored XSS can lead to a range of malicious outcomes, including session hijacking, theft of cookies or credentials, defacement, or pivoting to further attacks within the victim’s environment. The vulnerability is rated medium severity with a CVSS 3.1 base score of 6.1, reflecting network attack vector, low attack complexity, no privileges required, but requiring user interaction and impacting confidentiality and integrity with a scope change. No patches or official fixes are currently linked, and no known exploits have been observed in the wild. The vulnerability affects a widely used WordPress plugin, which is popular among websites that use Contact Form 7 for form data management. The plugin’s broad deployment increases the potential attack surface. The vulnerability’s exploitation does not require authentication, making it accessible to remote attackers. However, user interaction is necessary to trigger the malicious script execution. The stored nature of the XSS means that once injected, the malicious payload persists and can affect multiple users. The vulnerability is cataloged under CWE-79, which covers improper neutralization of input during web page generation. Given the plugin’s role in handling form data, the ‘tmpD’ parameter likely relates to temporary data storage or processing, which is insufficiently sanitized before output. This flaw underscores the importance of rigorous input validation and output encoding in web applications, especially plugins that handle user-generated content. Organizations using this plugin should monitor for updates or patches from the vendor and consider immediate mitigations to reduce risk.

The impact of CVE-2025-6740 is significant for organizations running WordPress sites with the Contact Form 7 Database Addon plugin. Successful exploitation allows attackers to inject persistent malicious scripts that execute in the browsers of site visitors or administrators. This can lead to session hijacking, credential theft, unauthorized actions performed on behalf of users, defacement of websites, and potential spread of malware. The compromise of administrative accounts could lead to full site takeover, data breaches, or further exploitation of internal networks. Since the vulnerability requires no authentication, attackers can remotely target any vulnerable site. The medium CVSS score reflects moderate impact on confidentiality and integrity but no direct availability impact. However, the scope change indicates that the vulnerability can affect components beyond the plugin itself, potentially impacting the entire WordPress site and its users. Given WordPress’s extensive use globally, the vulnerability presents a broad attack surface. Organizations relying on this plugin for form data management face increased risk of reputational damage, loss of customer trust, and regulatory consequences if user data is compromised. The absence of known exploits in the wild suggests limited current exploitation but does not preclude future attacks, especially as proof-of-concept code may emerge. Overall, the vulnerability poses a credible threat to website security and user safety.

To mitigate CVE-2025-6740, organizations should take the following specific actions: 1) Immediately audit WordPress sites to identify installations of the Contact Form 7 Database Addon plugin and determine the version in use. 2) If an updated, patched version is released by the vendor, promptly apply the update to remediate the vulnerability. 3) In the absence of a patch, consider disabling or uninstalling the plugin to eliminate the attack vector. 4) Implement a Web Application Firewall (WAF) with rules to detect and block common XSS payloads, particularly targeting the ‘tmpD’ parameter or suspicious POST/GET requests. 5) Apply strict Content Security Policy (CSP) headers to restrict the execution of inline scripts and limit the domains from which scripts can be loaded, reducing the impact of injected scripts. 6) Conduct regular security scans and penetration tests focusing on XSS vulnerabilities in web applications and plugins. 7) Educate site administrators and users about the risks of clicking on suspicious links or interacting with untrusted content. 8) Monitor logs for unusual activity or repeated attempts to exploit the ‘tmpD’ parameter. 9) Employ input validation and output encoding best practices in custom code or other plugins to prevent similar vulnerabilities. 10) Maintain a robust backup and incident response plan to quickly recover from potential compromises. These targeted measures go beyond generic advice by focusing on the specific plugin, parameter, and attack vector involved.