The GutenBee – Gutenberg Blocks plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.20.1 via the gutenbee_file_and_ext_json function. This is due to a flawed strpos() substring check that only verifies whether the filename contains the string '.json' rather than confirming the filename ends with a .json extension, allowing double-extension filenames like shell.json.php to bypass validation. This makes it possible for authenticated attackers, with author-level access and above, to upload files that may be executable, which makes remote code execution possible.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:H8.8/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HOther