Description

A high privileged remote attacker can upload a .php file and then request it directly from /uploads/<filename>.php to achieve arbitrary code execution due to improper file type validation which could result in full system compromise.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.2",
  "pubDate": "2026-08-20T09:16:45.813Z",
  "pubdate": "2026-08-20T09:16:45.813Z",
  "executiveSummary": "An arbitrary file upload vulnerability exists due to improper file type validation mechanisms within the application. This security flaw enables a malicious actor with high privileges to upload executable PHP scripts directly to the server.\nThe primary impact of this vulnerability is Remote Code Execution (RCE), which can ultimately lead to a full system compromise. Because the application fails to adequately sanitize or restrict file extensions during the ingestion phase, malicious payloads can bypass intended security boundaries.\nThe vulnerability is exposed over the network, requiring high privileges to successfully initiate the attack vector. Once the unauthorized script is stored, subsequent direct requests to the predictable storage directory execute the payload within the context of the web server process.\nOrganizations operating affected systems face severe risk implications, including complete confidentiality, integrity, and availability loss of the underlying host. Mitigation requires enforcing strict input validation, implementing strict allowlisting for file extensions, and removing execution permissions from upload directories.",
  "technicalDetails": "The root cause of this vulnerability is the absence of robust input validation and file type enforcement logic within the file upload mechanism. The application fails to verify the true MIME type, content structure, or semantic integrity of uploaded payloads, relying instead on easily spoofed metadata or insecure extension checks.\nThe vulnerable component is the file ingestion and storage pipeline, specifically interfacing with the /uploads directory. The application accepts multipart form data containing malicious payloads and persists the raw file contents to disk without transforming or neutralizing potentially dangerous extensions such as .php.\nAttack requirements dictate that the threat actor must possess high privileges to access the administrative interface or upload functionality. Network exposure is present via standard HTTP/HTTPS protocols, allowing remote exploitation if the administrative boundary is accessible over the network.\nThe step-by-step attack flow proceeds as follows: First, the authenticated high-privileged attacker crafts a malicious payload encapsulated within a file bearing a .php extension. Second, the attacker submits this file through the application's file upload interface. Third, the application stores the raw file directly into the /uploads/<filename>.php path without sanitization or renaming. Fourth, the attacker issues a direct HTTP request to /uploads/<filename>.php.\nUpon receiving the direct request for the uploaded script, the web server passes the file to the PHP interpreter. The payload executes with the permissions of the web server user, yielding arbitrary code execution.\nPost-exploitation impact includes the deployment of webshells, internal network reconnaissance, data exfiltration, lateral movement, and full system compromise."
}