# CVE-2021-29439: Plugins can be installed with minimal admin privileges

> Users with minimal admin privileges can install plugins to achieve arbitrary code execution and privilege escalation in Grav CMS.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-wg37-cf5x-55hq

## What is CVE-2021-29439?

CVE-2021-29439 is a high-severity missing authorization vulnerability in getgrav grav-plugin-admin, published on 13 Apr 2021. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

The Grav admin plugin prior to version 1.10.11 does not correctly verify caller's privileges. As a consequence, users with the permission `admin.login` can install third-party plugins and their dependencies. By installing the right plugin, an attacker can obtain an arbitrary code execution primitive and elevate their privileges on the instance. The vulnerability has been addressed in version 1.10.11. As a mitigation blocking access to the `/admin` path from untrusted sources will reduce the probability of exploitation.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2021-29439?

It affects 1 product.


Products: Getgrav Grav Admin.

## How do I fix CVE-2021-29439?

No fix has been published for CVE-2021-29439 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-29439 being exploited?

There is no known exploitation of CVE-2021-29439 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-29439 and fix it if it is affected.

What it is: CVE-2021-29439 is a high-severity missing authorization vulnerability in getgrav grav-plugin-admin, published on 13 Apr 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-29439 in the wild and no public exploit code.

Affected product: getgrav grav-plugin-admin. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2021-29439/ (Markdown: https://insights.sbomify.com/CVE-2021-29439/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-29439
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-29439
- OSV: https://osv.dev/vulnerability/CVE-2021-29439

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-29439/
Summaries are generated and may contain mistakes; the official description above is the record.