============================================================================
Ubuntu Security Notice USN-2783-1
October 27, 2015

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

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

- Ubuntu 15.10
- Ubuntu 15.04
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS

Summary:

Several security issues were fixed in NTP.

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

Details:

Aleksis Kauppinen discovered that NTP incorrectly handled certain remote
config packets. In a non-default configuration, a remote authenticated
attacker could possibly use this issue to cause NTP to crash, resulting in
a denial of service. (CVE-2015-5146)

Miroslav Lichvar discovered that NTP incorrectly handled logconfig
directives. In a non-default configuration, a remote authenticated attacker
could possibly use this issue to cause NTP to crash, resulting in a denial
of service. (CVE-2015-5194)

Miroslav Lichvar discovered that NTP incorrectly handled certain statistics
types. In a non-default configuration, a remote authenticated attacker
could possibly use this issue to cause NTP to crash, resulting in a denial
of service. (CVE-2015-5195)

Miroslav Lichvar discovered that NTP incorrectly handled certain file
paths. In a non-default configuration, a remote authenticated attacker
could possibly use this issue to cause NTP to crash, resulting in a denial
of service, or overwrite certain files. (CVE-2015-5196, CVE-2015-7703)

Miroslav Lichvar discovered that NTP incorrectly handled certain packets.
A remote attacker could possibly use this issue to cause NTP to hang,
resulting in a denial of service. (CVE-2015-5219)

Aanchal Malhotra, Isaac E. Cohen, and Sharon Goldberg discovered that NTP
incorrectly handled restarting after hitting a panic threshold. A remote
attacker could possibly use this issue to alter the system time on clients.
(CVE-2015-5300)

It was discovered that NTP incorrectly handled autokey data packets. A
remote attacker could possibly use this issue to cause NTP to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2015-7691, CVE-2015-7692, CVE-2015-7702)

It was discovered that NTP incorrectly handled memory when processing
certain autokey messages. A remote attacker could possibly use this issue
to cause NTP to consume memory, resulting in a denial of service.
(CVE-2015-7701)

Aanchal Malhotra, Isaac E. Cohen, and Sharon Goldberg discovered that NTP
incorrectly handled rate limiting. A remote attacker could possibly use
this issue to cause clients to stop updating their clock. (CVE-2015-7704,
CVE-2015-7705)

Yves Younan discovered that NTP incorrectly handled logfile and keyfile
directives. In a non-default configuration, a remote authenticated attacker
could possibly use this issue to cause NTP to enter a loop, resulting in a
denial of service. (CVE-2015-7850)

Yves Younan and Aleksander Nikolich discovered that NTP incorrectly handled
ascii conversion. A remote attacker could possibly use this issue to cause
NTP to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2015-7852)

Yves Younan discovered that NTP incorrectly handled reference clock memory.
A malicious refclock could possibly use this issue to cause NTP to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2015-7853)

John D "Doug" Birdwell discovered that NTP incorrectly handled decoding
certain bogus values. An attacker could possibly use this issue to cause
NTP to crash, resulting in a denial of service. (CVE-2015-7855)

Stephen Gray discovered that NTP incorrectly handled symmetric association
authentication. A remote attacker could use this issue to possibly bypass
authentication and alter the system clock. (CVE-2015-7871)

In the default installation, attackers would be isolated by the NTP
AppArmor profile.

Update instructions:

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

Ubuntu 15.10:
  ntp                             1:4.2.6.p5+dfsg-3ubuntu8.1

Ubuntu 15.04:
  ntp                             1:4.2.6.p5+dfsg-3ubuntu6.2

Ubuntu 14.04 LTS:
  ntp                             1:4.2.6.p5+dfsg-3ubuntu2.14.04.5

Ubuntu 12.04 LTS:
  ntp                             1:4.2.6.p3+dfsg-1ubuntu3.6

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

References:
  http://www.ubuntu.com/usn/usn-2783-1
  CVE-2015-5146, CVE-2015-5194, CVE-2015-5195, CVE-2015-5196,
  CVE-2015-5219, CVE-2015-5300, CVE-2015-7691, CVE-2015-7692,
  CVE-2015-7701, CVE-2015-7702, CVE-2015-7703, CVE-2015-7704,
  CVE-2015-7705, CVE-2015-7850, CVE-2015-7852, CVE-2015-7853,
  CVE-2015-7855, CVE-2015-7871

Package Information:
  https://launchpad.net/ubuntu/+source/ntp/1:4.2.6.p5+dfsg-3ubuntu8.1
  https://launchpad.net/ubuntu/+source/ntp/1:4.2.6.p5+dfsg-3ubuntu6.2
  https://launchpad.net/ubuntu/+source/ntp/1:4.2.6.p5+dfsg-3ubuntu2.14.04.5
  https://launchpad.net/ubuntu/+source/ntp/1:4.2.6.p3+dfsg-1ubuntu3.6