---
title: "CVE-2021-21425: Unauthenticated Arbitrary YAML… | CubePath"
description: "Grav Admin Plugin is an HTML user interface that provides a way to configure Grav and create and modify pages. In versions 1.10.7 and earlier…"
language: en
source: https://cubepath.com/security/cve/CVE-2021-21425
---

# CVE-2021-21425: Unauthenticated Arbitrary YAML… | CubePath

## Description

Grav Admin Plugin is an HTML user interface that provides a way to configure Grav and create and modify pages. In versions 1.10.7 and earlier, an unauthenticated user can execute some methods of administrator controller without needing any credentials. Particular method execution will result in arbitrary YAML file creation or content change of existing YAML files on the system. Successfully exploitation of that vulnerability results in configuration changes, such as general site information change, custom scheduler job definition, etc. Due to the nature of the vulnerability, an adversary can change some part of the webpage, or hijack an administrator account, or execute operating system command under the context of the web-server user. This vulnerability is fixed in version 1.10.8\. Blocking access to the \`/admin\` path from untrusted sources can be applied as a workaround.

Official description from the CVE record, published by GitHub\_M. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2021-21425)

## Key data

### CVSS 3.1 Critical 9.3

Score published by GitHub\_M in the CVE record.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N

| Metric                 | Value   | What it means                                                                       |
| ---------------------- | ------- | ----------------------------------------------------------------------------------- |
| Attack vector          | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity      | Low     | No special conditions are needed. The attack can be repeated at will.               |
| Privileges required    | None    | No account or privileges are needed.                                                |
| User interaction       | None    | No action from any user is needed.                                                  |
| Scope                  | Changed | The impact can reach other components beyond the vulnerable one.                    |
| Confidentiality impact | Low     | Limited effect on the secrecy of data.                                              |
| Integrity impact       | High    | Serious or total effect on the trustworthiness of data.                             |
| Availability impact    | None    | No effect on availability.                                                          |

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) .

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.80467 (80.5% probability)

Percentile

99.6%

Scores of

Nov 10, 2026

Model

v2026.06.15

### Weakness (CWE)

CWE catalog version 5.0.

CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.

- [CWE-284](https://cwe.mitre.org/data/definitions/284.html) Improper Access Control

## Affected products

Products listed in the CVE record, as the CNA published them.

- getgrav grav-plugin-admin

  - affected: <= 1.10.7

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [pentest.blog/unexpected-journey-7-gravcms-unauthenticated-a…](https://pentest.blog/unexpected-journey-7-gravcms-unauthenticated-arbitrary-yaml-write-update-leads-to-code-execution/)
- [github.com/getgrav/grav-plugin-admin/security/advisories/GH…](https://github.com/getgrav/grav-plugin-admin/security/advisories/GHSA-6f53-6qgv-39pj)
- [packetstormsecurity.com/files/162283/GravCMS-1.10.7-Remote-…](http://packetstormsecurity.com/files/162283/GravCMS-1.10.7-Remote-Command-Execution.html)
- [packetstormsecurity.com/files/162457/GravCMS-1.10.7-Remote-…](http://packetstormsecurity.com/files/162457/GravCMS-1.10.7-Remote-Command-Execution.html)

## Timeline

1. ID reserved Dec 22, 2020
2. Record published Apr 7, 2021
3. Record last updated Aug 3, 2024

## Look up another CVE

## About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

[Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection)

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 20:05 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)