CVE-2026-84171 in images upload on piclect Plugin
Summary
by MITRE • 09/12/2026
The WP images upload on piclect WordPress plugin through 1.0 does not validate the name or type of uploaded files before writing them to a publicly accessible directory, allowing unauthenticated attackers to upload arbitrary files and execute arbitrary code on the server.
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Analysis
by VulDB Data Team • 09/12/2026
The vulnerability identified in the Piclect WordPress plugin version 1.0 represents a critical security flaw rooted in improper input validation during file handling operations. Specifically, the images upload functionality fails to adequately verify the filename or MIME type of user-supplied files prior to persisting them on the server filesystem. This lack of rigorous sanitization and extension checking allows unauthenticated attackers to bypass standard web application defenses that typically rely on client-side checks or basic server-side validation rules. By exploiting this deficiency, an attacker can upload malicious scripts disguised as legitimate image files into a publicly accessible directory within the WordPress installation structure.
From a technical perspective, the core issue lies in the absence of strict allow-listing for file extensions and content types. Instead of verifying that uploaded data conforms to expected formats such as JPEG or PNG with corresponding headers, the application accepts any file type provided by the client request. This behavior creates a direct path for remote code execution because web servers are generally configured to execute scripts located in directories where they can be accessed via HTTP requests. When an attacker uploads a PHP shell or similar executable script under the guise of an image, subsequent access to that file triggers server-side interpretation and execution of the malicious payload.
The operational impact of this vulnerability is severe, as it effectively grants unauthenticated remote code execution capabilities to any internet user with knowledge of the target site's URL structure. Once executed, the arbitrary code can be leveraged to compromise the entire web application environment. Attackers may use this access to deface websites, steal sensitive data including database credentials and user information, install backdoors for persistent access, or pivot further into internal network segments if the server is part of a larger infrastructure. The lack of authentication requirement means that automated scanning tools can easily discover and exploit this weakness across thousands of WordPress sites running vulnerable versions of the plugin without any prior interaction or login.
This vulnerability aligns with CWE-434, which describes the unrestricted upload of files with dangerous types, as well as CWE-20, indicating improper input validation. In terms of attack vectors mapped to the MITRE ATT&CK framework, this scenario corresponds to T1505.003, Server Software Component: Web Shell, where attackers deploy web shells for persistent access and lateral movement. The exploitation path also reflects aspects of CWE-79 if cross-site scripting is facilitated through stored malicious content, though the primary risk here remains server-side code execution.
To mitigate this vulnerability, immediate action is required to update or remove the Piclect WordPress plugin to a patched version that implements robust file validation mechanisms. Administrators should ensure that uploaded files are validated against an allow-list of safe extensions and MIME types using both client-side and server-side checks. Additionally, implementing strict directory permissions where upload folders do not have execute privileges for web scripts can provide a layer of defense-in-depth. Regular security audits and the use of Web Application Firewalls configured to detect malicious file uploads can further reduce the risk of exploitation until patches are fully deployed across all affected systems.