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Server-Side Request Forgery (SSRF)

CVE-2021-40109

Severity Medium
Score 6.4/10

Summary

A SSRF issue was discovered in Concrete CMS through 8.5.5. Users can access forbidden files on their local network. A user with permissions to upload files from external sites can upload a URL that redirects to an internal resource of any file type. The redirect is followed and loads the contents of the file from the redirected-to server. Files of disallowed types can be uploaded.

  • LOW
  • NETWORK
  • LOW
  • CHANGED
  • NONE
  • LOW
  • LOW
  • NONE

CWE-918 - Server-Side Request Forgery (SSRF)

Server-side request forgery (SSRF) is a weakness that allows an attacker to send an arbitrary request, making it appear that the request was sent by the server. This request may bypass a firewall that would normally prevent direct access to the URL. The impact of this vulnerability can vary from unauthorized access to files and sensitive information to remote code execution.

Advisory Timeline

  • Published