Advisories

Grav before 1.0.3 Remote Code Execution via File Upload Extension Bypass

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severity
high
date
Affecting
  • grav >= 0, < 1.0.3

CWE
  • CWE-434 Unrestricted Upload of File with Dangerous Type
CVSS
5.3
CVSS V4 Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Credit
alienkeric
Description
The Grav API plugin (getgrav/grav-plugin-api) before 1.0.3 contains a file upload extension bypass in the API media controller. HandlesMediaUploads::validateFileExtension() inspects only the final file extension via pathinfo($filename, PATHINFO_EXTENSION), so a user with api.media.write permission can upload a file with a double extension such as shell.php.jpg to bypass the dangerous extensions blocklist. The web server may then execute the file as PHP, resulting in remote code execution.

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