如何仅列出或者安装RHEL 5.x或者CentOS Linux服务器下的安全更新？
如何找到每个补丁的安全更新描述，例如CVE，错误，发布日期和类型？

您可以使用yum-security插件轻松找到与安全补丁相关的信息。
该插件将选项security，cve，bz和advisory标志添加到yum以及list-security和info-security命令。
这些选项可以将软件包的列表/升级限制为特定于安全性的软件包。
这些命令为您提供安全信息。

安装插件

执行以下命令：

# yum install yum-security

如何显示可用的安全更新？

执行以下命令：

# yum list-security

输出示例：

Loaded plugins: rhnplugin, security
RHSA-2009:1148-1 security httpd-2.2.3-22.el5_3.2.x86_64
RHSA-2009:1148-1 security httpd-devel-2.2.3-22.el5_3.2.i386
RHSA-2009:1148-1 security httpd-manual-2.2.3-22.el5_3.2.x86_64
RHSA-2009:1148-1 security mod_ssl-1:2.2.3-22.el5_3.2.x86_64
list-security done

要列出所有与安全性相关的更新，并获取有关是否存在安全性更新的代码，请使用：

# yum --security check-update

要获取已安装软件包固定的所有BZ的列表，请使用：

# yum list-security bugzillas

要获取有关RHSA-2009：1148-1咨询的信息，请使用：

# yum info-security RHSA-2009:1148-1

输出示例：

Loaded plugins: rhnplugin, security

===============================================================================
  RHSA-2009:1148
===============================================================================
  Update ID : RHSA-2009:1148-1
    Release : 
       Type : security
     Status : final
     Issued : 2009-07-08 23:00:00
       Bugs : 509125 - None
	    : 509375 - None
       CVEs : CVE-2009-1890
	    : CVE-2009-1891
Description : Important: httpd security update  \The Apache HTTP Server is a
            : popular Web server.  A denial of service flaw was
            : found in the Apache mod_proxy module when it was
            : used as a reverse proxy. A remote attacker could
            : use this flaw to force a proxy process to consume
            : large amounts of CPU time. (CVE-2009-1890)  A
            : denial of service flaw was found in the Apache
            : mod_deflate module. This module continued to
            : compress large files until compression was
            : complete, even if the network connection that
            : requested the content was closed before
            : compression completed. This would cause
            : mod_deflate to consume large amounts of CPU if
            : mod_deflate was enabled for a large file.
            : (CVE-2009-1891)  All httpd users should upgrade to
            : these updated packages, which contain backported
            : patches to correct these issues. After installing
            : the updated packages, the httpd daemon must be
            : restarted for the update to take effect.
      Files : mod_ssl-2.2.3-22.el5_3.2.x86_64.rpm
	    : httpd-devel-2.2.3-22.el5_3.2.i386.rpm
	    : httpd-2.2.3-22.el5_3.2.x86_64.rpm
	    : httpd-devel-2.2.3-22.el5_3.2.x86_64.rpm
	    : httpd-manual-2.2.3-22.el5_3.2.x86_64.rpm
	    : mod_ssl-2.2.3-22.el5_3.2.i386.rpm
	    : httpd-2.2.3-22.el5_3.2.i386.rpm
	    : httpd-manual-2.2.3-22.el5_3.2.i386.rpm
info-security done

获取包含Bugzilla 3595修复程序的最新软件包的信息列表； CVE CVE-2009-1890和通报RHSA-2009：1148-1，使用：

# yum --bz 3595 --cve CVE-2009-1890 --advisory RHSA-2009:1148-1 info updates

如何仅安装所有安全更新？

执行以下命令以下载并安装所有可用的安全更新：

# yum update --security