Nexpose Vulnerability Database

NTP clock variables information disclosure

Severity	CVSS	Published	Added	Modified
Moderate (1)	0.0 (AV:N/AC:L/Au:N/C:N/I:N/A:N)	May 6, 2009	Apr 1, 2011	Apr 1, 2011

Description:

This sytem allows the internal NTP variables to be queried. These variables contain potentially sensitive information, such as the NTP software version, operating system version, peers, and more.

Solution:

• Disable NTP readvar queries

  Apply a restrict option to all hosts that are not authorized to perform NTP readvar queries. For example, to deny readvar requests from all clients, put the following in the NTP configuration file, typically /etc/ntp.conf, and restart the NTP service:

        restrict default mask 0.0.0.0 noquery 
      

• Cisco

  Restrict NTP readvar queries

  Apply an ACL that restricts NTP readvar queries from unauthorized clients, as described in the 'Configuring NTP Access Restrictions' section of the Cisco IOS documentation.

  Alternatively, if NTP is not required, disable it entirely by running the following command:

        ntp disable