CentOS 升级 Bash — 修复破壳漏洞

因为很多公司都有自己的 yum 源，所以直接配置其他的 yum 源升级的话是不允许的，为了能方便的升级，并且安全的测试，先拿一台测试机做测试。

CentOS 的修复方案

安装 yum 插件 yum-downloadonly

注： yum-downloadonly 插件的作用是实现只下载所需包而不直接安装

sudo yum -y install yum-downloadonly

添加 CentOS 的官方源 CentOS-Base.repo

CentOS 5 的官方源

# CentOS-Base.repo # # The mirror system uses the connecting IP address of the client and the # update status of each mirror to pick mirrors that are updated to and # geographically close to the client. You should use this for CentOS updates # unless you are manually picking other mirrors. # # If the mirrorlist= does not work for you, as a fall back you can try the # remarked out baseurl= line instead. # # [base] name=CentOS-$releasever – Base mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os #baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5 #released updates [updates] name=CentOS-$releasever – Updates mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates #baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5 #additional packages that may be useful [extras] name=CentOS-$releasever – Extras mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras #baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-$releasever – Plus mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus #baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/ gpgcheck=1 enabled=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5 #contrib – packages by Centos Users [contrib] name=CentOS-$releasever – Contrib mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib #baseurl=http://mirror.centos.org/centos/$releasever/contrib/$basearch/ gpgcheck=1 enabled=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

CentOS 6 的官方源

# CentOS-Base.repo # # The mirror system uses the connecting IP address of the client and the # update status of each mirror to pick mirrors that are updated to and # geographically close to the client. You should use this for CentOS updates # unless you are manually picking other mirrors. # # If the mirrorlist= does not work for you, as a fall back you can try the # remarked out baseurl= line instead. # # [base] name=CentOS-$releasever – Base mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os #baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 #released updates [updates] name=CentOS-$releasever – Updates mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates #baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 #additional packages that may be useful [extras] name=CentOS-$releasever – Extras mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras #baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-$releasever – Plus mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus #baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/ gpgcheck=1 enabled=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 #contrib – packages by Centos Users [contrib] name=CentOS-$releasever – Contrib mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib #baseurl=http://mirror.centos.org/centos/$releasever/contrib/$basearch/ gpgcheck=1 enabled=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

下载最新的 bash 包

把最新版本的 bash 的 rpm 包下载到 /tmp 目录

sudo yum -y install –downloadonly –downloaddir=/tmp/ bash

下载后的包名分别如下：

CentOS 5

bash-3.2-33.el5_10.4.x86_64.rpm

CentOS 6

bash-4.1.2-15.el6_5.2.x86_64.rpm

安装最新的 bash 包

CentOS 5

sudo yum -y install bash-3.2-33.el5_10.4.x86_64.rpm

CentOS 6

sudo yum -y install bash-4.1.2-15.el6_5.2.x86_64.rpm

验证

env X=() { (a)=> sh -c “echo date”; cat echo 输出如下：

date Mon Sep 29 10:11:56 CST 2014

env VAR=() { :;}; echo Bash is vulnerable! bash -c “echo Bash Hello” 输出如下：

Bash Hello

证明修复成功

加入现有的 rpm 源

最后一步就是把测试完成的包加入公司自己的源中，然后全网推送了。