📄 suexec.html.en
字号:
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
This file is generated from xml source: DO NOT EDIT
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
-->
<title>suEXEC Support - Apache HTTP Server</title>
<link href="./style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
<link href="./style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
<link href="./style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
<link href="./images/favicon.ico" rel="shortcut icon" /></head>
<body id="manual-page"><div id="page-header">
<p class="menu"><a href="./mod/">Modules</a> | <a href="./mod/directives.html">Directives</a> | <a href="./faq/">FAQ</a> | <a href="./glossary.html">Glossary</a> | <a href="./sitemap.html">Sitemap</a></p>
<p class="apache">Apache HTTP Server Version 2.0</p>
<img alt="" src="./images/feather.gif" /></div>
<div class="up"><a href="./"><img title="<-" alt="<-" src="./images/left.gif" /></a></div>
<div id="path">
<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="./">Version 2.0</a></div><div id="page-content"><div id="preamble"><h1>suEXEC Support</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="./en/suexec.html" title="English"> en </a> |
<a href="./ja/suexec.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
<a href="./ko/suexec.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p>
</div>
<p>The <strong>suEXEC</strong> feature provides
Apache users the ability
to run <strong>CGI</strong> and <strong>SSI</strong> programs
under user IDs different from the user ID of the calling
web-server. Normally, when a CGI or SSI program executes, it
runs as the same user who is running the web server.</p>
<p>Used properly, this feature can reduce
considerably the security risks involved with allowing users to
develop and run private CGI or SSI programs. However, if suEXEC
is improperly configured, it can cause any number of problems
and possibly create new holes in your computer's security. If
you aren't familiar with managing <em>setuid root</em> programs
and the security issues they present, we highly recommend that
you not consider using suEXEC.</p>
</div>
<div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#before">Before we begin</a></li>
<li><img alt="" src="./images/down.gif" /> <a href="#model">suEXEC Security Model</a></li>
<li><img alt="" src="./images/down.gif" /> <a href="#install">Configuring & Installing
suEXEC</a></li>
<li><img alt="" src="./images/down.gif" /> <a href="#enable">Enabling & Disabling
suEXEC</a></li>
<li><img alt="" src="./images/down.gif" /> <a href="#usage">Using suEXEC</a></li>
<li><img alt="" src="./images/down.gif" /> <a href="#debug">Debugging suEXEC</a></li>
<li><img alt="" src="./images/down.gif" /> <a href="#jabberwock">Beware the Jabberwock:
Warnings & Examples</a></li>
</ul></div>
<div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
<div class="section">
<h2><a name="before" id="before">Before we begin</a></h2>
<p>Before jumping head-first into this document,
you should be aware of the assumptions made on the part of the
Apache Group and this document.</p>
<p>First, it is assumed that you are using a UNIX
derivative operating system that is capable of
<strong>setuid</strong> and <strong>setgid</strong> operations.
All command examples are given in this regard. Other platforms,
if they are capable of supporting suEXEC, may differ in their
configuration.</p>
<p>Second, it is assumed you are familiar with
some basic concepts of your computer's security and its
administration. This involves an understanding of
<strong>setuid/setgid</strong> operations and the various
effects they may have on your system and its level of
security.</p>
<p>Third, it is assumed that you are using an
<strong>unmodified</strong> version of suEXEC code. All code
for suEXEC has been carefully scrutinized and tested by the
developers as well as numerous beta testers. Every precaution
has been taken to ensure a simple yet solidly safe base of
code. Altering this code can cause unexpected problems and new
security risks. It is <strong>highly</strong> recommended you
not alter the suEXEC code unless you are well versed in the
particulars of security programming and are willing to share
your work with the Apache Group for consideration.</p>
<p>Fourth, and last, it has been the decision of
the Apache Group to <strong>NOT</strong> make suEXEC part of
the default installation of Apache. To this end, suEXEC
configuration requires of the administrator careful attention
to details. After due consideration has been given to the
various settings for suEXEC, the administrator may install
suEXEC through normal installation methods. The values for
these settings need to be carefully determined and specified by
the administrator to properly maintain system security during
the use of suEXEC functionality. It is through this detailed
process that the Apache Group hopes to limit suEXEC
installation only to those who are careful and determined
enough to use it.</p>
<p>Still with us? Yes? Good. Let's move on!</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
<div class="section">
<h2><a name="model" id="model">suEXEC Security Model</a></h2>
<p>Before we begin configuring and installing
suEXEC, we will first discuss the security model you are about
to implement. By doing so, you may better understand what
exactly is going on inside suEXEC and what precautions are
taken to ensure your system's security.</p>
<p><strong>suEXEC</strong> is based on a setuid
"wrapper" program that is called by the main Apache web server.
This wrapper is called when an HTTP request is made for a CGI
or SSI program that the administrator has designated to run as
a userid other than that of the main server. When such a
request is made, Apache provides the suEXEC wrapper with the
program's name and the user and group IDs under which the
program is to execute.</p>
<p>The wrapper then employs the following process
to determine success or failure -- if any one of these
conditions fail, the program logs the failure and exits with an
error, otherwise it will continue:</p>
<ol>
<li>
<strong>Is the user executing this wrapper a valid user of
this system?</strong>
<p class="indent">
This is to ensure that the user executing the wrapper is
truly a user of the system.
</p>
</li>
<li>
<strong>Was the wrapper called with the proper number of
arguments?</strong>
<p class="indent">
The wrapper will only execute if it is given the proper
number of arguments. The proper argument format is known
to the Apache web server. If the wrapper is not receiving
the proper number of arguments, it is either being
hacked, or there is something wrong with the suEXEC
portion of your Apache binary.
</p>
</li>
<li>
<strong>Is this valid user allowed to run the
wrapper?</strong>
<p class="indent">
Is this user the user allowed to run this wrapper? Only
one user (the Apache user) is allowed to execute this
program.
</p>
</li>
<li>
<strong>Does the target CGI or SSI program have an unsafe
hierarchical reference?</strong>
<p class="indent">
Does the target CGI or SSI program's path contain a leading
'/' or have a '..' backreference? These are not allowed; the
target CGI/SSI program must reside within suEXEC's document
root (see <code>--with-suexec-docroot=<em>DIR</em></code>
below).
</p>
</li>
<li>
<strong>Is the target user name valid?</strong>
<p class="indent">
Does the target user exist?
</p>
</li>
<li>
<strong>Is the target group name valid?</strong>
<p class="indent">
Does the target group exist?
</p>
</li>
<li>
<strong>Is the target user <em>NOT</em> superuser?</strong>
<p class="indent">
Presently, suEXEC does not allow <code><em>root</em></code>
to execute CGI/SSI programs.
</p>
</li>
<li>
<strong>Is the target userid <em>ABOVE</em> the minimum ID
number?</strong>
<p class="indent">
The minimum user ID number is specified during
configuration. This allows you to set the lowest possible
userid that will be allowed to execute CGI/SSI programs.
This is useful to block out "system" accounts.
</p>
</li>
<li>
<strong>Is the target group <em>NOT</em> the superuser
group?</strong>
<p class="indent">
Presently, suEXEC does not allow the <code><em>root</em></code>
group to execute CGI/SSI programs.
</p>
</li>
<li>
<strong>Is the target groupid <em>ABOVE</em> the minimum ID
number?</strong>
<p class="indent">
The minimum group ID number is specified during
configuration. This allows you to set the lowest possible
groupid that will be allowed to execute CGI/SSI programs.
This is useful to block out "system" groups.
</p>
</li>
<li>
<strong>Can the wrapper successfully become the target user
and group?</strong>
<p class="indent">
Here is where the program becomes the target user and
group via setuid and setgid calls. The group access list
is also initialized with all of the groups of which the
user is a member.
</p>
</li>
<li>
<strong>Can we change directory to the one in which the target
CGI/SSI program resides?</strong>
<p class="indent">
If it doesn't exist, it can't very well contain files. If we
can't change directory to it, it might aswell not exist.
</p>
</li>
<li>
<strong>Is the directory within the Apache
webspace?</strong>
<p class="indent">
If the request is for a regular portion of the server, is
the requested directory within suEXEC's document root? If
the request is for a UserDir, is the requested directory
within the directory configured as suEXEC's userdir (see
<a href="#install">suEXEC's configuration options</a>)?
</p>
</li>
<li>
<strong>Is the directory <em>NOT</em> writable by anyone
else?</strong>
<p class="indent">
We don't want to open up the directory to others; only
the owner user may be able to alter this directories
contents.
</p>
</li>
<li>
<strong>Does the target CGI/SSI program exist?</strong>
<p class="indent">
If it doesn't exists, it can't very well be executed.
</p>
</li>
<li>
<strong>Is the target CGI/SSI program <em>NOT</em> writable
by anyone else?</strong>
<p class="indent">
We don't want to give anyone other than the owner the
ability to change the CGI/SSI program.
</p>
</li>
<li>
<strong>Is the target CGI/SSI program <em>NOT</em> setuid or
setgid?</strong>
<p class="indent">
We do not want to execute programs that will then change
our UID/GID again.
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -