如何为redhat5升级bash，防止bash漏洞呢,参阅http://down.51cto.com/data/194201

1、到centos官网下载 yum-3.2.22-40.el5.centos.noarch.rpm、yum-metadata-parser-1.1.2-4.el5.i386.rpm、python-iniparse-0.2.3.6-el5.noarch.rpm、yum-fastestmirror-1.1.16-21.el5.centos.noarch.rpm，四个文件，建议到centos.ustc.edu.cn的镜像中去找

2、卸载redhat自带的yum， rpm -aq|grep yum|xargs rpm -e --nodeps

3、执行以下命令进行安装yum 

    rpm -ivh python-iniparse-0.2.3-6.el5.noarch.rpm

    rpm -ivh yum-metadata-parser-1.1.2-4.el5.i386.rpm

    rpm -ivh yum-3.2.22-40.el5.centos.noarch,rpm yum-fastestmirror-1.1.16-21.el5.centos.noarch.rpm

4、vi /etc/yum.repos.d/CentOS-Base.repo

      [base]

      name=CentOS-5 -Base

      baseurl=http://mirrors.ustc.edu.cn/centos/5/os/i386/

      gpgcheck=0

      enabled=1

     [updates]

     name=CentOS-5 -Update

     baseurl=http://mirrors.ustc.edu.cn/centos/5/updates/i386/

     gpgcheck=0

     enabled=1

5、测试 yum list

6、yum update bash -y