CVE-2025-53309 is a vulnerability classified under CWE-201, which involves the insertion of sensitive information into sent data within the ZealousWeb plugin "Accept Stripe Payments Using Contact Form 7." This plugin integrates Stripe payment processing capabilities into websites using the Contact Form 7 WordPress plugin. The vulnerability allows an attacker to retrieve embedded sensitive data that should not be exposed during the data transmission process. Specifically, the flaw arises when sensitive information, potentially including payment or personal data, is improperly inserted or included in the data sent from the plugin, making it accessible to unauthorized parties. The vulnerability affects all versions up to 3.0, with no specific fixed version currently indicated. The CVSS 3.1 base score is 5.3, indicating a medium severity level. The vector string (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N) shows that the vulnerability is remotely exploitable over the network without requiring privileges or user interaction, but the impact is limited to a low confidentiality loss without affecting integrity or availability. No known exploits are currently reported in the wild, and no patches have been published yet. The vulnerability's root cause is related to improper handling of sensitive data insertion into outbound data streams, which could lead to unintended data disclosure during payment processing workflows on affected websites.

For European organizations using the ZealousWeb Accept Stripe Payments Using Contact Form 7 plugin, this vulnerability poses a risk of unauthorized disclosure of sensitive payment or personal information. Although the confidentiality impact is rated low, any leakage of payment data can have serious compliance implications under the EU's GDPR regulations, potentially leading to fines and reputational damage. The vulnerability could be exploited remotely without authentication, increasing the risk of automated scanning and data harvesting attacks. E-commerce sites, non-profits, and service providers relying on this plugin for payment processing are particularly at risk. The lack of integrity or availability impact means that the core payment processing functionality remains intact, but the exposure of sensitive data could undermine customer trust and lead to secondary attacks such as phishing or fraud. Given the widespread use of WordPress and Contact Form 7 in Europe, the vulnerability could affect a significant number of small to medium enterprises that rely on this plugin for Stripe payments.

European organizations should immediately audit their use of the ZealousWeb Accept Stripe Payments Using Contact Form 7 plugin and monitor for any updates or patches from the vendor. In the absence of an official patch, organizations should consider temporarily disabling the plugin or replacing it with alternative, more secure payment integration methods. Implementing strict web application firewall (WAF) rules to detect and block suspicious requests targeting the plugin's endpoints can reduce exposure. Additionally, organizations should review their payment data handling policies to ensure sensitive information is not unnecessarily logged or transmitted in clear text. Conducting regular security assessments and penetration tests focusing on payment workflows can help identify any data leakage. Finally, organizations should ensure that all payment data is transmitted over encrypted channels (TLS) and that Stripe API keys and credentials are securely stored and rotated regularly.