CVE-2021-22968 Improper file handling in concrete5/core
Admins can bypass file extension restrictions to upload and execute malicious code via remote file staging in Concrete CMS.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-22968?
CVE-2021-22968 is a high-severity vulnerability in Concretecms Concrete Cms, published on 19 Nov 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
A bypass of adding remote files in Concrete CMS (previously concrete5) File Manager leads to remote code execution in Concrete CMS (concrete5) versions 8.5.6 and below.The external file upload feature stages files in the public directory even if they have disallowed file extensions. They are stored in a directory with a random name, but it's possible to stall the uploads and brute force the directory name. You have to be an admin with the ability to upload files, but this bug gives you the ability to upload restricted file types and execute them depending on server configuration.To fix this, a check for allowed file extensions was added before downloading files to a tmp directory.Concrete CMS Security Team gave this a CVSS v3.1 score of 5.4 AV:N/AC:H/PR:H/UI:R/S:C/C:N/I:H/A:NThis fix is also in Concrete version 9.0.0
Which versions are affected by CVE-2021-22968?
2 open source packages ship an affected version, including concrete5/core. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
concrete5/core Packagist | All versions | 8.5.7 |
concrete5/core Packagist | All versions | 8.5.7 |
Products include Concretecms Concrete Cms.
How do I fix CVE-2021-22968?
Upgrade concrete5/core to 8.5.7 or later.
Is CVE-2021-22968 being exploited?
There is no known exploitation of CVE-2021-22968 in the wild and no public exploit code.
Other vulnerabilities in Concretecms Concrete Cms
- CVE-2023-48648 Concrete CMS allows unauthorized access because directories can be created with insecure permissions
- CVE-2022-21829 Code injection in concrete CMS
- CVE-2021-22958 Server-Side Request Forgery vulnerability in concrete5
- CVE-2021-40098 Path traversal in n/a
- CVE-2026-8134 Concrete CMS Vulnerable to Relative Path Traversal
Sources
Also known as GHSA-g3p2-hfqr-9m25.