In iOS before 11.4 and macOS High Sierra before 10.13.5, a memory corruption issue exists and was addressed with improved memory handling.
https://support.apple.com/HT208848,
Source: MITRE
Published: 2019-01-11
Updated: 2019-01-23
Type: CWE-119
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