==========================================================================
Ubuntu Security Notice USN-3707-1
July 09, 2018

ntp vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 17.10
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in NTP.

Software Description:
- ntp: Network Time Protocol daemon and utility programs

Details:

Yihan Lian discovered that NTP incorrectly handled certain malformed mode 6
packets. A remote attacker could possibly use this issue to cause ntpd to
crash, resulting in a denial of service. This issue only affected Ubuntu
17.10 and Ubuntu 18.04 LTS. (CVE-2018-7182)

Michael Macnair discovered that NTP incorrectly handled certain responses.
A remote attacker could possibly use this issue to execute arbitrary code.
(CVE-2018-7183)

Miroslav Lichvar discovered that NTP incorrectly handled certain
zero-origin timestamps. A remote attacker could possibly use this issue to
cause a denial of service. This issue only affected Ubuntu 17.10 and Ubuntu
18.04 LTS. (CVE-2018-7184)

Miroslav Lichvar discovered that NTP incorrectly handled certain
zero-origin timestamps. A remote attacker could possibly use this issue to
cause a denial of service. (CVE-2018-7185)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 18.04 LTS:
  ntp                             1:4.2.8p10+dfsg-5ubuntu7.1

Ubuntu 17.10:
  ntp                             1:4.2.8p10+dfsg-5ubuntu3.3

Ubuntu 16.04 LTS:
  ntp                             1:4.2.8p4+dfsg-3ubuntu5.9

Ubuntu 14.04 LTS:
  ntp                             1:4.2.6.p5+dfsg-3ubuntu2.14.04.13

In general, a standard system update will make all the necessary changes.

References:
  https://usn.ubuntu.com/usn/usn-3707-1
  CVE-2018-7182, CVE-2018-7183, CVE-2018-7184, CVE-2018-7185

Package Information:
  https://launchpad.net/ubuntu/+source/ntp/1:4.2.8p10+dfsg-5ubuntu7.1
  https://launchpad.net/ubuntu/+source/ntp/1:4.2.8p10+dfsg-5ubuntu3.3
  https://launchpad.net/ubuntu/+source/ntp/1:4.2.8p4+dfsg-3ubuntu5.9
  https://launchpad.net/ubuntu/+source/ntp/1:4.2.6.p5+dfsg-3ubuntu2.14.04.13