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sudo yum install yum-security |
To list all updates that are security relevant, and get a reutrn code on whether there are security updates use:
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sudo yum --security check-update |
To apply updates that are security relevant use:
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sudo yum --security update |
Ubuntu (command line):
Update the Package Index: The APT package index is essentially a database of available packages from the repositories defined in the /etc/apt/sources.list file.
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The Prevention
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1. If you plan to continue running NTP, ensure it is upgraded to 4.2.6, or later. ITS Networking operates two NTPv4 (NTP version 4) free of charge: 128.83.185.40 (ntp1.utexas.edu) or 128.83.185.41 (ntp2.utexas.edu)
2. Review NTP access restrictions and adjust as needed. Refer to the following
resources: http://support.ntp.org/bin/view/Support/AccessRestrictions
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Example 1: edit /etc/inet/ntp.client -> ntp.conf added: #added for DDoS prevention - don't allow any machine, except those w/o flags Example 2 (with additional comments): # Permit time synchronization with our time source, but do not # permit the source to query or modify the service on this system. restrict default ignore restrict -6 default ignore #restrict default kod nomodify notrap nopeer noquery #restrict -6 default kod nomodify notrap nopeer noquery # Permit all access over the loopback interface. This could # be tightened as well, but to do so would effect some of # the administrative functions. restrict 127.0.0.1 server 128.83.185.40 restrict 128.83.185.40 nomodify notrap nopeer noquery server 128.83.185.41 restrict 128.83.185.41 nomodify notrap nopeer noquery ~~~~~~~~`` default servers are commented out # Use public servers from the pool.ntp.org project. # Please consider joining the pool (http://www.pool.ntp.org/join.html). #server 0.centos.pool.ntp.org iburst #server 1.centos.pool.ntp.org iburst #server 2.centos.pool.ntp.org iburst #server 3.centos.pool.ntp.org iburst |
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