Description

The DS Ad Rotator WordPress plugin through 0.8 does not perform any capability check, nonce verification, or file-type validation on its image upload handler, allowing unauthenticated attackers to upload arbitrary files, including PHP, to a web-accessible directory, which can lead to remote code execution.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-09-12T06:16:25.730Z",
  "pubdate": "2026-09-12T06:16:25.730Z",
  "executiveSummary": "The DS Ad Rotator WordPress plugin, in versions through 0.8, is susceptible to an unauthenticated arbitrary file upload vulnerability. This security flaw stems from a complete lack of access control, nonce verification, and file type validation within the plugin's image upload handler.\nThe vulnerability allows remote, unauthenticated attackers to upload malicious files, such as PHP web shells, directly to a web-accessible directory on the WordPress installation. Successful exploitation results in Remote Code Execution (RCE), granting the attacker the ability to execute arbitrary commands on the underlying server with the privileges of the web server user.\nGiven the absence of authentication requirements, this vulnerability poses a critical risk to site integrity, confidentiality, and availability. Attackers can leverage this entry point to perform full system compromise, data exfiltration, or lateral movement within the hosting environment. There are no requirements for valid user credentials or pre-existing administrative access to initiate an attack, making it a high-priority threat for any WordPress deployment running affected versions of the plugin.",
  "technicalDetails": "The root cause of this vulnerability is the implementation of an insecure image upload handler within the DS Ad Rotator plugin. The handler functions as an unrestricted entry point that processes HTTP POST requests containing file data without verifying the identity of the requester. By omitting nonce verification, the plugin fails to protect against Cross-Site Request Forgery (CSRF) and direct unauthenticated interaction with the upload logic.\nFurthermore, the handler lacks server-side file type validation. This means the system does not inspect the MIME type, magic bytes, or file extension of the uploaded content. Consequently, the application will accept any file, including executable PHP scripts, regardless of the intended use case for image rotation. Because the upload destination is within a web-accessible directory, the server can serve and execute these files once accessed via a standard browser request.\nThe attack flow proceeds as follows: First, an unauthenticated attacker identifies the vulnerable upload endpoint. Second, the attacker crafts an HTTP request containing a malicious payload, typically a PHP web shell designed for arbitrary command execution. Third, the attacker sends this request directly to the plugin's upload function. Because there is no capability check (e.g., checking for 'manage_options' or 'upload_files' capabilities), the plugin processes the request and saves the malicious script to the server's filesystem.\nOnce the file is successfully placed on the server, the attacker determines the file path and triggers the execution of the web shell by sending an HTTP GET request to the uploaded file's URL. Upon execution, the payload runs in the context of the web server process, providing the attacker with a remote command-line interface. Post-exploitation, an attacker can maintain persistence, modify WordPress core files, inject malicious redirects, access sensitive database information, or pivot to other systems accessible from the compromised server. The lack of strict filesystem permissions or upload directory restrictions further exacerbates the impact of this vulnerability by allowing the malicious script to function effectively in the environment."
}