CVE-2021-22969 Server-Side Request Forgery in Concrete CMS
Attackers can bypass SSRF protections via DNS rebinding to fetch cloud IAM keys from local network services.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-22969?
CVE-2021-22969 is a medium-severity server-side request forgery vulnerability in Concretecms Concrete Cms, published on 19 Nov 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Concrete CMS (formerly concrete5) versions below 8.5.7 has a SSRF mitigation bypass using DNS Rebind attack giving an attacker the ability to fetch cloud IAAS (ex AWS) IAM keys.To fix this Concrete CMS no longer allows downloads from the local network and specifies the validated IP when downloading rather than relying on DNS.Discoverer: Adrian Tiron from FORTBRIDGE ( https://www.fortbridge.co.uk/ )The Concrete CMS team gave this a CVSS 3.1 score of 3.5 AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N . Please note that Cloud IAAS provider mis-configurations are not Concrete CMS vulnerabilities. A mitigation for this vulnerability is to make sure that the IMDS configurations are according to a cloud provider's best practices.This fix is also in Concrete version 9.0.0
Weakness: CWE-918
Which versions are affected by CVE-2021-22969?
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-2021-22969?
Upgrade concrete5/core to 8.5.7 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2021-22969 being exploited?
There is no known exploitation of CVE-2021-22969 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-mcxr-fx5f-96qq.