IOKit SCSI in Apple iOS before 9.2, OS X before 10.11.2, tvOS before 9.1, and watchOS before 2.1 allows attackers to execute arbitrary code in a privileged context or cause a denial of service (NULL pointer dereference) via an app that provides an unspecified userclient type.
http://lists.apple.com/archives/security-announce/2015/Dec/msg00000.html
http://lists.apple.com/archives/security-announce/2015/Dec/msg00001.html
http://lists.apple.com/archives/security-announce/2015/Dec/msg00002.html
http://lists.apple.com/archives/security-announce/2015/Dec/msg00005.html
http://www.securityfocus.com/bid/78719
http://www.securitytracker.com/id/1034344
https://support.apple.com/HT205635
https://support.apple.com/HT205637
Source: MITRE
Published: 2015-12-11
Updated: 2019-03-25
Type: CWE-476
Base Score: 9.3
Vector: AV:N/AC:M/Au:N/C:C/I:C/A:C
Impact Score: 10
Exploitability Score: 8.6
Severity: HIGH
Base Score: 7.8
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 1.8
Severity: HIGH