How to repair problems with historical Linux images

This article introduces how to repair problems with historical Linux images, and focuses on the specific steps. The content of this article is compact, and I hope you can gain something from it.

Problem fixing plan for historical Linux images

ECS cloud servers created with historical Linux images may have NTP not configured, YUM not configured, and may also have security vulnerabilities that have recently been exposed. Please follow the steps below to repair it to make your cloud server more secure. You can also use the YUM service provided by Alibaba Cloud to install the software, and you can use the free NTP provided by Alibaba Cloud for time synchronization.

1. Configure NTP

Does not distinguish between distribution versions. First back up /etc/ntp.conf, and then replace its content with the following:

# ntp.conf
#
# ntpd config for aliyun ecs.
#
# 6LAN+6LAN+3WAN
#               shijun.cao@alibaba-inc.com
#               2014.8.11
#
driftfile  /var/lib/ntp/drift
pidfile   /var/run/ntpd.pid
logfile /var/log/ntp.log
# Access Control Support
restrict    default ignore
restrict -6 default ignore
restrict 127.0.0.1
restrict 192.168.0.0 mask 255.255.0.0 nomodify notrap nopeer noquery
restrict 172.16.0.0 mask 255.240.0.0 nomodify notrap nopeer noquery
restrict 100.64.0.0 mask 255.192.0.0 nomodify notrap nopeer noquery
restrict 10.0.0.0 mask 255.0.0.0 nomodify notrap nopeer noquery
restrict ntp1.aliyun.com nomodify notrap nopeer noquery
restrict ntp2.aliyun.com nomodify notrap nopeer noquery
restrict ntp3.aliyun.com nomodify notrap nopeer noquery
restrict ntp4.aliyun.com nomodify notrap nopeer noquery
restrict ntp5.aliyun.com nomodify notrap nopeer noquery
restrict ntp6.aliyun.com nomodify notrap nopeer noquery
# local clock
server 127.127.1.0
fudge  127.127.1.0 stratum 10
#public ntp server
server ntp1.aliyun.com iburst minpoll 4 maxpoll 10
server ntp2.aliyun.com iburst minpoll 4 maxpoll 10
server ntp3.aliyun.com iburst minpoll 4 maxpoll 10
server ntp4.aliyun.com iburst minpoll 4 maxpoll 10
server ntp5.aliyun.com iburst minpoll 4 maxpoll 10
server ntp6.aliyun.com iburst minpoll 4 maxpoll 10
#Private ntp server
server ntp1.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp2.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp3.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp4.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp5.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp6.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
#New private ntp server
server ntp7.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp8.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp9.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp10.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp11.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
server ntp12.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10

2. Update the software source

0. First confirm the current Linux system release and version number of the image.

If there is lsb_release command, execute:

lsb_release -a

Otherwise, execute

cat /etc/issue

1. For CentOS, backup /etc/yum.repos.d/ CentOS-Base.repo and epel.repo files under the CentOS version, execute the following corresponding commands according to the CentOS version:

CentOS 5:

wget -qO /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo
wget -qO /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-5.repo
CentOS 6:
wget -qO /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
wget -qO /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
CentOS 7:
wget -qO /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
wget -qO /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

After the repo file is downloaded, execute:

yum makecache

2. For Aliyun 5.7, back up /etc/yum.repos.d/CentOS-Base.repo, and then execute:

wget -qO /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/aliyun-5.repo

After the repo file is downloaded , execute:

yum makecache

3. For Ubuntu, back up the /etc/apt/sources.list file. According to the distribution version, execute the command:

ubuntu12.04:
wget -qO  /etc/apt/sources.list http://mirrors.aliyun.com/repo/ubuntu1204-lts.list
ubuntu14.04:
wget -qO  /etc/apt/sources.list http://mirrors.aliyun.com/repo/ubuntu1404-lts.list

and then execute:

apt-get update

4. For Debian, back up the /etc/apt/sources.list file. According to the distribution version, execute the command:

debian6:
wget -qO /etc/apt/sources.list http://mirrors.aliyun.com/repo/debian6-lts.list
debian7:
wget -qO /etc/apt/sources.list http://mirrors.aliyun.com/repo/debian7-lts.list

and then execute:

apt-get update

3. Security vulnerability repair patch

mainly repairs currently known major security vulnerabilities. Software that needs to be upgraded includes: bash, glibc, openssl, wget, ntp.

Before executing the following command, you need to ensure that the current software source of the system has been set correctly.

1. For CentOS and Aliyun Linux, execute:

yum update bash glibc openssl wget ntp

2. For Ubuntu and Debian, execute:

apt-get install bash libc6 libc-bin openssl wget ntp

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