4.6 - USN-175-1

Executive Summary

Summary
Title	ntp server vulnerability

Informations
Name	USN-175-1	First vendor Publication	2005-09-01
Vendor	Ubuntu	Last vendor Modification	2005-09-01
Severity (Vendor)	N/A	Revision	N/A

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score	NA
Base Score	NA	Environmental Score	NA
impact SubScore	NA	Temporal Score	NA
Exploitabality Sub Score	NA

Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:L/AC:L/Au:N/C:P/I:P/A:P)
Cvss Base Score	4.6	Attack Range	Local
Cvss Impact Score	6.4	Attack Complexity	Low
Cvss Expoit Score	3.9	Authentication	None Required
Calculate full CVSS 2.0 Vectors scores

Detail

A security issue affects the following Ubuntu releases:

Ubuntu 4.10 (Warty Warthog)

The following packages are affected:

ntp-refclock ntp-server ntp-simple

The problem can be corrected by upgrading the affected package to version 1:4.2.0a-10ubuntu2.1. In general, a standard system upgrade is sufficient to effect the necessary changes.

Details follow:

Thomas Biege discovered a flaw in the privilege dropping of the NTP server. When ntpd was configured to drop root privileges, and the group to run under was specified as a name (as opposed to a numeric group ID), ntpd changed to the wrong group. Depending on the actual group it changed to, this could either cause non-minimal privileges, or a malfunctioning ntp server if the group does not have the privileges that ntpd actually needs.

On Ubuntu 4.10, ntpd does not use privilege dropping by default, so you are only affected if you manually activated it. In Ubuntu 5.04, privilege dropping is used by default, but this bug is already fixed.