CVE-2024-9939 is a path traversal vulnerability categorized under CWE-22 found in the WordPress File Upload plugin developed by nickboss. This vulnerability exists in all versions up to and including 4.24.13 and is exploitable via the wfu_file_downloader.php endpoint. The flaw arises from improper validation and limitation of file pathnames, allowing attackers to manipulate the file path parameter to access files outside the designated upload directory. Because the vulnerability is exploitable over the network without authentication or user interaction, attackers can remotely read arbitrary files on the server, potentially including sensitive configuration files, credentials, or other critical data. The vulnerability does not allow modification or deletion of files, so integrity and availability impacts are not present. The CVSS v3.1 base score is 7.5, reflecting a high severity level due to the ease of exploitation and the potential confidentiality breach. No patches or official fixes are currently linked, and no known exploits have been reported in the wild as of the publication date. However, the widespread deployment of WordPress and the popularity of this plugin increase the risk of exploitation once proof-of-concept code becomes available.

The primary impact of this vulnerability is unauthorized disclosure of sensitive information stored on the web server hosting the vulnerable WordPress plugin. Attackers can read arbitrary files, which may include database credentials, private keys, configuration files, or other sensitive data that could facilitate further attacks such as privilege escalation, lateral movement, or data breaches. This compromises the confidentiality of the affected systems. Since the vulnerability does not allow file modification or deletion, integrity and availability impacts are minimal. However, the exposure of sensitive data can have severe consequences for organizations, including regulatory non-compliance, reputational damage, and financial loss. Given the plugin’s widespread use in WordPress sites globally, especially in small to medium businesses and content-heavy websites, the potential attack surface is large. Organizations relying on this plugin without mitigation are at risk of data leakage and subsequent targeted attacks.

To mitigate CVE-2024-9939, organizations should immediately update the WordPress File Upload plugin to a version that addresses this vulnerability once available. In the absence of an official patch, administrators should consider disabling the vulnerable wfu_file_downloader.php functionality or restricting access to it via web server configuration (e.g., IP whitelisting or authentication). Implementing web application firewall (WAF) rules to detect and block path traversal patterns in HTTP requests targeting this endpoint can provide temporary protection. Additionally, file system permissions should be reviewed and hardened to limit the web server’s access to sensitive files outside the intended directories. Monitoring web server logs for suspicious access attempts to wfu_file_downloader.php and unusual file access patterns is recommended. Finally, organizations should conduct a thorough audit of exposed files and credentials in case of prior exploitation and rotate any compromised secrets.