In Expression Engine before 6.0.3, addonIcon in Addons/file/mod.file.php relies on the untrusted input value of input->get('file') instead of the fixed file names of icon.png and icon.svg.
https://github.com/ExpressionEngine/ExpressionEngine/releases/tag/6.0.3
https://github.com/ExpressionEngine/ExpressionEngine/compare/6.0.1...6.0.3#diff-17bcb23e5666fc2dccb79c7133e9eeb701847f67ae84fbde0a673c3fd3d109e0R508
Source: Mitre, NVD
Published: 2021-08-12
Updated: 2021-08-23
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
EPSS: 0.00433