An issue was discovered in phpMyAdmin. It is possible to bypass AllowRoot restriction ($cfg['Servers'][$i]['AllowRoot']) and deny rules for username by using Null Byte in the username. All 4.6.x versions (prior to 4.6.5), 4.4.x versions (prior to 4.4.15.9), and 4.0.x versions (prior to 4.0.10.18) are affected.
http://www.securityfocus.com/bid/94521
https://lists.debian.org/debian-lts-announce/2019/06/msg00009.html
Source: MITRE
Published: 2016-12-11
Updated: 2017-07-01
Type: CWE-264
Base Score: 7.5
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 10
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
Impact Score: 5.9
Exploitability Score: 3.9
Severity: CRITICAL