HIGH
The crontab script in the ntp package before 1:4.2.6.p3+dfsg-1ubuntu3.11 on Ubuntu 12.04 LTS, before 1:4.2.6.p5+dfsg-3ubuntu2.14.04.10 on Ubuntu 14.04 LTS, on Ubuntu Wily, and before 1:4.2.8p4+dfsg-3ubuntu5.3 on Ubuntu 16.04 LTS allows local users with access to the ntp account to write to arbitrary files and consequently gain privileges via vectors involving statistics directory cleanup.
http://packetstormsecurity.com/files/141913/NTP-Privilege-Escalation.html
http://www.securityfocus.com/bid/81552
http://www.securitytracker.com/id/1034808
http://www.ubuntu.com/usn/USN-3096-1
Source: MITRE
Published: 2017-04-14
Updated: 2017-04-20
Type: CWE-264
Base Score: 7.2
Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C
Impact Score: 10
Exploitability Score: 3.9
Severity: HIGH
Base Score: 7.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 1.8
Severity: HIGH