CVE-2021-21425 CRITICAL

CVE-2021-21425: Unauthenticated Arbitrary YAML Write/Update leads to Code Execution

Vendor Getgrav
Product grav-plugin-admin
Weakness CWE-284
Published April 7, 2021
Last update August 3, 2024

CVSS base score

9.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity High

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 7, 2021 CVE published
August 3, 2024 Record updated