# 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.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Nov 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-mcxr-fx5f-96qq

## 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 (Server-Side Request Forgery)

## Which versions are affected by CVE-2021-22969?

2 open source packages ship an affected version, including concrete5/core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `concrete5/core` | Packagist | All versions | 8.5.7 |
| `concrete5/core` | Packagist | All versions | 8.5.7 |

Products: Concretecms Concrete Cms.

## How do I fix CVE-2021-22969?

Upgrade concrete5/core to 8.5.7 or later.

## 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](https://insights.sbomify.com/CVE-2023-48648/): Concrete CMS allows unauthorized access because directories can be created with insecure permissions (critical 9.8)
- [CVE-2022-21829](https://insights.sbomify.com/CVE-2022-21829/): Code injection in concrete CMS (critical 9.8)
- [CVE-2021-22958](https://insights.sbomify.com/CVE-2021-22958/): Server-Side Request Forgery vulnerability in concrete5 (critical 9.8)
- [CVE-2021-40098](https://insights.sbomify.com/CVE-2021-40098/): Path traversal in n/a (critical 9.8)
- [CVE-2026-8134](https://insights.sbomify.com/CVE-2026-8134/): Concrete CMS Vulnerable to Relative Path Traversal (critical 9.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22969 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2021-22969 in the wild and no public exploit code.

Affected packages and fixed versions:
- concrete5/core (Packagist): affected all versions; fixed in 8.5.7
- concrete5/core (Packagist): affected all versions; fixed in 8.5.7

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-22969/ (Markdown: https://insights.sbomify.com/CVE-2021-22969/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22969
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22969
- OSV: https://osv.dev/vulnerability/CVE-2021-22969

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22969/
Summaries are generated and may contain mistakes; the official description above is the record.