CVE-2024-13339 is a security vulnerability classified as CWE-352 (Cross-Site Request Forgery) found in the DeBounce Email Validator plugin for WordPress, affecting all versions up to and including 5.6.6. The vulnerability stems from the plugin's failure to properly implement nonce validation on its administrative 'debounce_email_validator' page. Nonces are security tokens used to ensure that requests made to a web application are intentional and originate from legitimate users. Without correct nonce validation, attackers can craft malicious requests that, when executed by an authenticated administrator (e.g., by clicking a specially crafted link), cause unauthorized changes to the plugin's settings or inject malicious web scripts. This attack vector does not require the attacker to be authenticated but does require social engineering to convince an admin to perform the action. The vulnerability impacts the confidentiality and integrity of the affected WordPress site by enabling unauthorized configuration changes and potential script injection, which could lead to further compromise. The CVSS v3.1 base score is 6.1, indicating a medium severity level, with the vector string AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N, meaning it is remotely exploitable over the network with low attack complexity, no privileges required, but requires user interaction, and affects 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 was published on February 19, 2025, and was assigned by Wordfence.

The primary impact of this vulnerability is unauthorized modification of the DeBounce Email Validator plugin settings and potential injection of malicious scripts into the WordPress site. This can lead to compromised site integrity and confidentiality, as attackers may alter email validation behavior or insert scripts that could steal sensitive information, perform further attacks such as privilege escalation, or facilitate phishing. Since the attack requires an administrator to be tricked into clicking a malicious link, the risk is somewhat mitigated by user interaction requirements but remains significant given the high privileges of administrators. Organizations relying on this plugin for email validation risk unauthorized configuration changes that could disrupt email workflows or expose user data. Additionally, injected scripts could be used to pivot attacks within the site or to visitors, potentially damaging reputation and trust. The vulnerability does not directly affect availability but could indirectly cause service disruptions if exploited to compromise the site. Given WordPress's widespread use globally, many organizations using this plugin could be affected, especially those with less stringent administrative security practices.

To mitigate this vulnerability, organizations should immediately update the DeBounce Email Validator plugin once a patched version is released. In the absence of an official patch, administrators should consider temporarily disabling the plugin or restricting access to the 'debounce_email_validator' admin page to trusted IP addresses only. Implementing Web Application Firewall (WAF) rules to detect and block suspicious CSRF attempts targeting this plugin can reduce risk. Educate site administrators on the dangers of clicking untrusted links, especially when logged into WordPress admin accounts. Additionally, site owners can implement custom nonce validation or security plugins that enforce strict CSRF protections on admin pages. Regularly auditing plugin permissions and monitoring for unusual configuration changes can help detect exploitation attempts early. Finally, maintaining up-to-date backups and incident response plans will aid recovery if exploitation occurs.