The Linux kernel, as used in Red Hat Enterprise Linux 7, kernel-rt, and Enterprise MRG 2 and when booted with UEFI Secure Boot enabled, allows local users to bypass intended securelevel/secureboot restrictions by leveraging improper handling of secure_boot flag across kexec reboot.
https://github.com/mjg59/linux/commit/4b2b64d5a6ebc84214755ebccd599baef7c1b798
https://bugzilla.redhat.com/show_bug.cgi?id=1272472
http://www.openwall.com/lists/oss-security/2015/10/15/6
http://rhn.redhat.com/errata/RHSA-2015-2411.html
Source: MITRE
Published: 2017-09-19
Updated: 2017-10-05
Type: CWE-254
Base Score: 2.1
Vector: AV:L/AC:L/Au:N/C:N/I:P/A:N
Impact Score: 2.9
Exploitability Score: 3.9
Severity: LOW
Base Score: 5.5
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Impact Score: 3.6
Exploitability Score: 1.8
Severity: MEDIUM