All vulnerabilities

Servers and applications

CVE-2021-40109

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.

Severity
Medium 6.4
Published
27 Sept 2021
Last changed
17 Jun 2026
Added to UpHeron
1 Nov 2026
Fixed in
8.5.6
Sources
NVD

Affected software

SoftwareAffected versions
Concrete CMSServers and applications · cpe:a:concretecms:concrete_cms
  • Every version before 8.5.6

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2021-40109
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2021-40109