CVE-2025-6740 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Contact Form 7 Database Addon – CFDB7 plugin for WordPress, developed by arshidkv12. This vulnerability affects all versions up to and including 1.3.1. The root cause is improper neutralization of input during web page generation, specifically insufficient sanitization and escaping of the 'tmpD' parameter. An unauthenticated attacker can exploit this flaw by injecting arbitrary malicious scripts into the plugin's stored data. These scripts execute in the context of any user who views the affected page, potentially leading to session hijacking, defacement, or redirection to malicious sites. The vulnerability is classified under CWE-79, which pertains to improper input validation leading to XSS. The CVSS v3.1 base score is 6.1 (medium severity), reflecting that the attack vector is network-based (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R). The scope is changed (S:C), indicating the vulnerability affects components beyond the vulnerable one. The impact affects confidentiality and integrity but not availability. No known exploits are currently reported in the wild, and no patches have been linked yet. Given the widespread use of WordPress and the popularity of Contact Form 7 and its addons, this vulnerability poses a significant risk to websites using this plugin, especially those that do not sanitize user inputs or restrict access to form data pages. Attackers can leverage this to compromise site visitors or administrators by injecting persistent malicious scripts that execute upon page load.

For European organizations, this vulnerability can lead to several adverse outcomes. Stored XSS can enable attackers to steal session cookies or authentication tokens from users, potentially leading to unauthorized access to sensitive data or administrative functions. This is particularly critical for organizations handling personal data under GDPR, as data breaches can result in regulatory penalties and reputational damage. Additionally, attackers could deface websites or redirect users to phishing or malware distribution sites, undermining trust and brand integrity. Since the vulnerability requires no authentication, any public-facing WordPress site using the vulnerable plugin is at risk. The medium severity score indicates moderate risk, but the potential for chained attacks or exploitation in combination with other vulnerabilities could elevate the threat. European organizations with customer-facing portals, e-commerce sites, or internal portals using this plugin are especially vulnerable. The lack of a patch at the time of disclosure increases the urgency for mitigation. Furthermore, the scope change in the CVSS vector suggests that the impact could extend beyond the plugin itself, potentially affecting other components or user sessions.

1. Immediate mitigation should include disabling or removing the Contact Form 7 Database Addon – CFDB7 plugin until a patch is released. 2. Implement Web Application Firewall (WAF) rules to detect and block malicious payloads targeting the 'tmpD' parameter or suspicious script injections in form submissions. 3. Restrict access to pages displaying stored form data to trusted users only, employing strong authentication and authorization controls. 4. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on affected pages. 5. Conduct thorough input validation and output encoding on all user-supplied data, especially parameters like 'tmpD', to prevent injection of executable code. 6. Monitor logs for unusual activity or repeated attempts to inject scripts via form inputs. 7. Educate site administrators and developers on the risks of stored XSS and best practices for secure coding and plugin management. 8. Once available, promptly apply official patches or updates from the plugin vendor. 9. Consider isolating the plugin's data display pages in a sandboxed environment or separate domain/subdomain to limit the impact of any successful exploitation.