CVE-2024-8756 is a vulnerability classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) affecting the Quform WordPress Form Builder plugin developed by ThemeCatcher. The issue exists in all versions up to and including 2.20.0 within the 'saveUploadedFile' function, which handles files uploaded through forms. Due to improper access controls or insufficient validation, unauthenticated attackers can retrieve sensitive data such as Personally Identifiable Information (PII) from these uploaded files. The vulnerability is particularly insidious because it does not require any authentication or user interaction, making it accessible remotely over the network. Furthermore, even after upgrading to the patched version 2.21.0, files uploaded via forms created before the upgrade remain exposed, as the vulnerability affects stored files rather than just the plugin code. To fully remediate, administrators must download and securely delete all previously uploaded files and recreate forms post-upgrade. The CVSS v3.1 base score is 5.3 (medium), reflecting the ease of exploitation (network, no privileges, no user interaction) but limited impact (confidentiality loss only, no integrity or availability impact). No known exploits have been reported in the wild, but the widespread use of WordPress and this popular form plugin increases the potential attack surface.

The primary impact of this vulnerability is unauthorized disclosure of sensitive information, including Personally Identifiable Information (PII), which can lead to privacy violations, regulatory non-compliance (e.g., GDPR, CCPA), and reputational damage for affected organizations. Attackers can extract uploaded files without authentication, potentially harvesting user-submitted data such as contact details, identification documents, or other confidential information. Although the vulnerability does not affect data integrity or availability, the exposure of sensitive data can facilitate further attacks such as identity theft, phishing, or social engineering. Organizations using the affected plugin versions are at risk, especially those handling sensitive user data through forms. The persistence of vulnerable files after patching increases the risk window and complicates remediation efforts. Given WordPress's global popularity and the plugin's usage, a large number of websites could be affected, including e-commerce, healthcare, education, and government sectors.

To mitigate CVE-2024-8756, site administrators should immediately upgrade the Quform plugin to version 2.21.0 or later, which contains the fix for the 'saveUploadedFile' function vulnerability. However, upgrading alone is insufficient because files uploaded via forms created before the upgrade remain exposed. Therefore, administrators must: 1) Identify and download all previously uploaded files stored by the plugin to secure offline storage; 2) Delete all previously existing uploaded files and associated forms from the WordPress installation to remove vulnerable data; 3) Recreate the forms anew after upgrading to ensure that new uploads are handled securely; 4) Review access permissions on upload directories to restrict unauthorized access; 5) Monitor web server logs for suspicious access attempts to uploaded files; 6) Consider implementing additional web application firewall (WAF) rules to block unauthorized file access; 7) Educate site users and administrators about the risk and remediation steps. Regular backups and security audits should be conducted to ensure no residual exposure remains.