An issue was discovered in Joomla! before 3.8.12. Inadequate checks in the InputFilter class could allow specifically prepared phar files to pass the upload filter.
https://developer.joomla.org/security-centre/743-20180801-core-hardening-the-inputfilter-for-phar-stubs.html
http://www.securitytracker.com/id/1041913
http://www.securityfocus.com/bid/105166
Source: Mitre, NVD
Published: 2018-08-29
Updated: 2018-11-05
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