Description

File Upload vulnerability in RainyGao-Hithub DocSys v.2.02.80 allows a remote attacker to execute arbitrary code

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-08-17T20:16:45.137Z",
  "pubdate": "2026-08-17T20:16:45.137Z",
  "executiveSummary": "An arbitrary file upload vulnerability has been identified in RainyGao-Hithub DocSys v.2.02.80, which permits remote attackers to execute arbitrary code on the underlying host system. The vulnerability stems from insufficient validation and sanitization of uploaded file characteristics, allowing threat actors to bypass restrictions and upload malicious executables or scripts directly to the web server.\nThe primary impact of successful exploitation includes remote code execution (RCE), complete system compromise, unauthorized access to sensitive application data, and potential lateral movement within the network architecture. The affected product is DocSys version v.2.02.80, developed by RainyGao-Hithub.\nThe risk implications are critical, as an unauthenticated or remote attacker can leverage this flaw to subvert application integrity and operational availability. The attacker capabilities involve interacting with the file upload functionality to deliver and trigger malicious payloads. Exploitation requires network access to the vulnerable DocSys instance and the ability to submit HTTP requests targeting the file upload interface.",
  "technicalDetails": "The vulnerability resides within the file upload component of DocSys version v.2.02.80. The root cause of the security flaw is the inadequate verification of file extensions, MIME types, and internal file signatures during the file intake process. When a user uploads a file through the application interface, the system fails to adequately restrict the storage of executable scripts or enforce strict allow-lists for permitted file formats.\nExploitation occurs when a remote attacker crafts a malicious payload, such as a web shell or executable script corresponding to the server-side technology stack, and submits it via the vulnerable file upload mechanism. Because the application does not validate the file content or sanitize the destination file path, the malicious payload is written directly to a web-accessible directory on the server.\nThe attack flow proceeds as follows: First, the attacker identifies the file upload endpoint exposed by DocSys v.2.02.80. Second, the attacker uploads a polyglot file or a direct script disguised as an allowable document type, or leverages a total lack of extension filtering. Third, the application stores the uploaded file on the filesystem. Finally, the attacker issues a direct HTTP request to the location of the newly uploaded file, triggering execution by the web server parser and achieving remote code execution under the privileges of the web application process.\nNetwork exposure is remote, as the application interface is accessible over network protocols. Authentication and privilege requirements depend on the specific configuration of the upload endpoint; however, if the upload functionality is exposed without proper session validation, unauthenticated remote attackers can execute the attack. Post-exploitation impact encompasses full administrative control over the affected system, data exfiltration, installation of persistent backdoors, and compromise of adjacent network segments."
}