Arbitrary file upload in Form plugin for Grav CMS - CVE-2024-27923
Published: March 4, 2024 / Updated: May 20, 2026
Vulnerability identifier: #VU130048
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2024-27923
CWE-ID: CWE-434
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Grav CMS
Affected software:
Form plugin for Grav CMS
Form plugin for Grav CMS
Detailed vulnerability description
The vulnerability allows a remote user to execute arbitrary code.
The vulnerability exists due to improper access control and unrestricted upload of file with dangerous type in the frontmatter form handling feature when creating a page and submitting a crafted contact form. A remote user can add the data[_json][header][form] parameter to enable frontmatter, create a form that saves a .phar file, and submit PHP code to execute arbitrary code.
Exploitation requires an account capable of creating pages.
How to mitigate CVE-2024-27923
Install security update from vendor's website.