USN-2449-1: NTP vulnerabilities

22 December 2014

ntp vulnerabilities

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

  • Ubuntu 14.10
  • Ubuntu 14.04 LTS
  • Ubuntu 12.04 LTS
  • Ubuntu 10.04 LTS

Summary

Several security issues were fixed in NTP.

Software Description

  • ntp - Network Time Protocol daemon and utility programs

Details

Neel Mehta discovered that NTP generated weak authentication keys. A remote attacker could possibly use this issue to brute force the authentication key and send requests if permitted by IP restrictions. (CVE-2014-9293)

Stephen Roettger discovered that NTP generated weak MD5 keys. A remote attacker could possibly use this issue to brute force the MD5 key and spoof a client or server. (CVE-2014-9294)

Stephen Roettger discovered that NTP contained buffer overflows in the crypto_recv(), ctl_putdata() and configure() functions. In non-default configurations, a remote attacker could use these issues to cause NTP to crash, resulting in a denial of service, or possibly execute arbitrary code. The default compiler options for affected releases should reduce the vulnerability to a denial of service. In addition, attackers would be isolated by the NTP AppArmor profile. (CVE-2014-9295)

Stephen Roettger discovered that NTP incorrectly continued processing when handling certain errors. (CVE-2014-9296)

Update instructions

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

Ubuntu 14.10
ntp - 1:4.2.6.p5+dfsg-3ubuntu2.14.10.1
Ubuntu 14.04 LTS
ntp - 1:4.2.6.p5+dfsg-3ubuntu2.14.04.1
Ubuntu 12.04 LTS
ntp - 1:4.2.6.p3+dfsg-1ubuntu3.2
Ubuntu 10.04 LTS
ntp - 1:4.2.4p8+dfsg-1ubuntu2.2

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system update you need to regenerate any MD5 keys that were manually created with ntp-keygen.

References