CVE-2020-36705 in Adning Advertising Plugin
Summary
by MITRE • 06/07/2023
The Adning Advertising plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the _ning_upload_image function in versions up to, and including, 1.5.5. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected sites server which may make remote code execution possible.
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Analysis
by VulDB Data Team • 04/09/2026
The Adning Advertising plugin for WordPress presents a critical security vulnerability classified as CVE-2020-36705, affecting versions up to and including 1.5.5. This vulnerability stems from inadequate input validation within the _ning_upload_image function, creating a pathway for unauthenticated attackers to exploit the system. The flaw represents a significant weakness in the plugin's file upload mechanism, where proper validation checks are absent or insufficient to prevent malicious file uploads. The vulnerability falls under the category of insecure file handling practices that have been documented in various security frameworks and standards.
The technical implementation of this vulnerability occurs within the plugin's core functionality where the _ning_upload_image function fails to validate file types before processing uploads. This missing validation allows attackers to bypass normal security restrictions and upload files with potentially dangerous extensions such as php, aspx, or other executable formats. The absence of proper file type checking creates an environment where attackers can upload malicious payloads that can be executed on the target server. This type of vulnerability is categorized as CWE-434, which specifically addresses the insecure upload of code or files that can lead to remote code execution. The flaw demonstrates a fundamental failure in input sanitization and access control mechanisms that should be implemented at multiple layers of the application.
The operational impact of this vulnerability extends beyond simple unauthorized file uploads, as it creates a potential gateway for complete system compromise. Unauthenticated attackers can leverage this vulnerability to upload backdoor files, web shells, or other malicious executables that can be executed with the privileges of the web server process. This capability enables attackers to gain persistent access to affected WordPress installations, potentially leading to data breaches, service disruption, or further lateral movement within network environments. The vulnerability directly maps to several tactics within the MITRE ATT&CK framework, particularly those related to initial access through web application attacks and privilege escalation via uploaded malicious files. Organizations running vulnerable versions of this plugin face significant risk of unauthorized access and potential compromise of their entire web infrastructure.
Mitigation strategies for this vulnerability require immediate action including updating to the latest version of the Adning Advertising plugin where the file validation has been properly implemented. System administrators should also implement additional security measures such as restricting file upload directories, implementing proper file type filtering at the web server level, and monitoring for suspicious file upload activities. The vulnerability highlights the importance of proper security testing and code review processes, particularly for plugins that handle user input or file operations. Organizations should conduct comprehensive vulnerability assessments to identify other potentially affected plugins or applications within their environment. Regular security audits and keeping all WordPress components updated are essential practices to prevent similar vulnerabilities from compromising system integrity. The incident underscores the necessity of following secure coding practices and implementing defense-in-depth strategies to protect against file upload related attacks that can have catastrophic consequences for web applications.