CVE-2023-6827 in Essential Real Estate Plugin
Summary
by MITRE • 12/15/2023
The Essential Real Estate plugin for WordPress is vulnerable to arbitrary file uploads due to insufficient file type validation on the 'ajaxUploadFonts' function in versions up to, and including, 4.3.5. This makes it possible for authenticated attackers with subscriber-level capabilities or above, to upload arbitrary files on the affected site's server which may make remote code execution possible. CVE-2023-6140 appears to be a duplicate of this issue.
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Analysis
by VulDB Data Team • 04/11/2026
The Essential Real Estate plugin for WordPress presents a critical security vulnerability through its 'ajaxUploadFonts' function that fails to properly validate file types during upload operations. This flaw exists in versions up to and including 4.3.5, creating a pathway for malicious actors to exploit the system's file handling mechanisms. The vulnerability stems from inadequate input sanitization and validation processes that allow attackers to bypass normal security restrictions imposed on file uploads. Security researchers have identified this weakness as a significant risk to WordPress installations that utilize this plugin, particularly when the plugin is actively used for font management features.
The technical implementation of this vulnerability allows authenticated users with subscriber-level privileges or higher to execute unauthorized file uploads to the target server. This occurs because the 'ajaxUploadFonts' function does not adequately verify the MIME types or file extensions of uploaded content, nor does it perform sufficient checks on file content to ensure legitimacy. Attackers can exploit this by crafting malicious files with extensions that appear legitimate but contain executable code or malicious payloads. The vulnerability essentially removes the barriers that should normally prevent users from uploading potentially harmful files to the web server's file system, creating a direct pathway for attackers to gain unauthorized control over the hosting environment.
The operational impact of this vulnerability extends beyond simple unauthorized file uploads, as it creates opportunities for remote code execution on the affected WordPress installations. When attackers successfully upload malicious files, they can potentially execute arbitrary code on the server, leading to complete system compromise. This risk is particularly severe because the vulnerability requires minimal privileges to exploit, making it accessible to users who normally have limited access rights within the WordPress environment. The consequences can include data theft, service disruption, unauthorized access to sensitive information, and potential use as a foothold for further attacks within the network infrastructure.
Security professionals should immediately address this vulnerability by updating to the latest version of the Essential Real Estate plugin where the file validation issues have been resolved. Organizations using this plugin should implement additional monitoring of file upload activities and conduct thorough security assessments of their WordPress installations. The vulnerability aligns with CWE-434 which specifically addresses insecure file upload handling, and represents a clear violation of secure coding practices that should prevent unrestricted file uploads. From an ATT&CK framework perspective, this vulnerability maps to techniques involving file execution and privilege escalation, potentially enabling adversaries to establish persistent access to compromised systems. Organizations should also consider implementing web application firewalls and restricting file upload capabilities to only trusted users with elevated privileges to minimize the risk of exploitation.