CVE-2025-1028 is a vulnerability classified under CWE-434 (Unrestricted Upload of File with Dangerous Type) found in the kleor Contact Manager plugin for WordPress. This plugin, widely used for managing contact forms, contains a flaw in its file upload functionality that fails to validate the type of files being uploaded. As a result, unauthenticated attackers can upload arbitrary files to the server hosting the WordPress site. The vulnerability is present in all versions up to and including 8.6.4. Exploitation is complex as it requires successfully exploiting a race condition during the upload process. Additionally, remote code execution (RCE) is possible in specific server configurations where the system processes the first file extension instead of the last, allowing attackers to bypass simple extension-based restrictions (e.g., uploading a file named shell.php.jpg that is interpreted as PHP). The CVSS v3.1 score is 8.1, reflecting high impact on confidentiality, integrity, and availability, with network attack vector, high attack complexity, no privileges or user interaction required, and unchanged scope. Although no known exploits are currently in the wild, the vulnerability poses a significant risk due to the potential for full server compromise. The lack of available patches at the time of disclosure increases urgency for mitigation. This vulnerability highlights the critical need for robust file type validation and secure handling of file uploads in web applications, especially plugins integrated into popular CMS platforms like WordPress.

The impact of CVE-2025-1028 is substantial for organizations running WordPress sites with the kleor Contact Manager plugin installed. Successful exploitation can lead to arbitrary file uploads, which may enable attackers to execute remote code on the web server, resulting in full system compromise. This jeopardizes the confidentiality of sensitive data stored or processed by the site, the integrity of the website content and backend systems, and the availability of the service if attackers deploy destructive payloads or ransomware. The vulnerability’s unauthenticated nature means attackers do not need valid credentials, increasing the attack surface. Exploiting the race condition adds complexity but does not eliminate risk, especially for skilled adversaries. Organizations could face data breaches, defacement, service outages, or use of compromised servers as pivot points for further attacks. The widespread use of WordPress globally and the popularity of contact form plugins amplify the potential scale of impact. Without timely remediation, affected sites remain vulnerable to targeted or opportunistic attacks, potentially damaging organizational reputation and incurring regulatory penalties if sensitive data is exposed.

To mitigate CVE-2025-1028, organizations should immediately assess if the kleor Contact Manager plugin is installed and in use on their WordPress sites. Since no official patches are available at disclosure, temporary mitigations include disabling the file upload feature within the plugin or removing the plugin entirely if it is not critical. Implement strict web application firewall (WAF) rules to detect and block suspicious file upload attempts, especially those containing multiple extensions or known malicious payload signatures. Employ server-side file type validation using MIME type checks and whitelist allowed file extensions rigorously. Monitor server logs for unusual upload activity or race condition exploitation attempts. Restrict file execution permissions in upload directories by configuring the web server to disallow execution of uploaded files (e.g., disabling PHP execution in upload folders). Regularly back up website data and test restoration procedures to minimize damage from potential exploitation. Stay alert for official patches or updates from the vendor and apply them promptly once released. Additionally, consider deploying runtime application self-protection (RASP) tools to detect and block exploitation attempts in real time.