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diff --git a/rubbos/app/apache2/manual/misc/security_tips.html.en b/rubbos/app/apache2/manual/misc/security_tips.html.en deleted file mode 100644 index 560c8259..00000000 --- a/rubbos/app/apache2/manual/misc/security_tips.html.en +++ /dev/null @@ -1,354 +0,0 @@ -<?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>Security Tips - 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> > <a href="./">Miscellaneous Documentation</a></div><div id="page-content"><div id="preamble"><h1>Security Tips</h1> -<div class="toplang"> -<p><span>Available Languages: </span><a href="../en/misc/security_tips.html" title="English"> en </a> | -<a href="../ko/misc/security_tips.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> | -<a href="../tr/misc/security_tips.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p> -</div> - - <p>Some hints and tips on security issues in setting up a web server. - Some of the suggestions will be general, others specific to Apache.</p> - </div> -<div id="quickview"><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#uptodate">Keep up to Date</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#serverroot">Permissions on ServerRoot Directories</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#ssi">Server Side Includes</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#cgi">CGI in General</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#nsaliasedcgi">Non Script Aliased CGI</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#saliasedcgi">Script Aliased CGI</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#dynamic">Other sources of dynamic content</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#systemsettings">Protecting System Settings</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#protectserverfiles">Protect Server Files by Default</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#watchyourlogs">Watching Your Logs</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="uptodate" id="uptodate">Keep up to Date</a></h2> - - <p>The Apache HTTP Server has a good record for security and a - developer community highly concerned about security issues. But - it is inevitable that some problems -- small or large -- will be - discovered in software after it is released. For this reason, it - is crucial to keep aware of updates to the software. If you have - obtained your version of the HTTP Server directly from Apache, we - highly recommend you subscribe to the <a href="http://httpd.apache.org/lists.html#http-announce">Apache - HTTP Server Announcements List</a> where you can keep informed of - new releases and security updates. Similar services are available - from most third-party distributors of Apache software.</p> - - <p>Of course, most times that a web server is compromised, it is - not because of problems in the HTTP Server code. Rather, it comes - from problems in add-on code, CGI scripts, or the underlying - Operating System. You must therefore stay aware of problems and - updates with all the software on your system.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="serverroot" id="serverroot">Permissions on ServerRoot Directories</a></h2> - - - - <p>In typical operation, Apache is started by the root user, and it - switches to the user defined by the <code class="directive"><a href="../mod/mpm_common.html#user">User</a></code> directive to serve hits. As is the - case with any command that root executes, you must take care that it is - protected from modification by non-root users. Not only must the files - themselves be writeable only by root, but so must the directories, and - parents of all directories. For example, if you choose to place - ServerRoot in <code>/usr/local/apache</code> then it is suggested that - you create that directory as root, with commands like these:</p> - - <div class="example"><p><code> - mkdir /usr/local/apache <br /> - cd /usr/local/apache <br /> - mkdir bin conf logs <br /> - chown 0 . bin conf logs <br /> - chgrp 0 . bin conf logs <br /> - chmod 755 . bin conf logs - </code></p></div> - - <p>It is assumed that <code>/</code>, <code>/usr</code>, and - <code>/usr/local</code> are only modifiable by root. When you install the - <code class="program"><a href="../programs/httpd.html">httpd</a></code> executable, you should ensure that it is - similarly protected:</p> - - <div class="example"><p><code> - cp httpd /usr/local/apache/bin <br /> - chown 0 /usr/local/apache/bin/httpd <br /> - chgrp 0 /usr/local/apache/bin/httpd <br /> - chmod 511 /usr/local/apache/bin/httpd - </code></p></div> - - <p>You can create an htdocs subdirectory which is modifiable by other - users -- since root never executes any files out of there, and shouldn't - be creating files in there.</p> - - <p>If you allow non-root users to modify any files that root either - executes or writes on then you open your system to root compromises. - For example, someone could replace the <code class="program"><a href="../programs/httpd.html">httpd</a></code> binary so - that the next time you start it, it will execute some arbitrary code. If - the logs directory is writeable (by a non-root user), someone could replace - a log file with a symlink to some other system file, and then root - might overwrite that file with arbitrary data. If the log files - themselves are writeable (by a non-root user), then someone may be - able to overwrite the log itself with bogus data.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="ssi" id="ssi">Server Side Includes</a></h2> - - - - <p>Server Side Includes (SSI) present a server administrator with - several potential security risks.</p> - - <p>The first risk is the increased load on the server. All - SSI-enabled files have to be parsed by Apache, whether or not - there are any SSI directives included within the files. While this - load increase is minor, in a shared server environment it can become - significant.</p> - - <p>SSI files also pose the same risks that are associated with CGI - scripts in general. Using the <code>exec cmd</code> element, SSI-enabled - files can execute any CGI script or program under the permissions of the - user and group Apache runs as, as configured in - <code>httpd.conf</code>.</p> - - <p>There are ways to enhance the security of SSI files while still - taking advantage of the benefits they provide.</p> - - <p>To isolate the damage a wayward SSI file can cause, a server - administrator can enable <a href="../suexec.html">suexec</a> as - described in the <a href="#cgi">CGI in General</a> section.</p> - - <p>Enabling SSI for files with <code>.html</code> or <code>.htm</code> - extensions can be dangerous. This is especially true in a shared, or high - traffic, server environment. SSI-enabled files should have a separate - extension, such as the conventional <code>.shtml</code>. This helps keep - server load at a minimum and allows for easier management of risk.</p> - - <p>Another solution is to disable the ability to run scripts and - programs from SSI pages. To do this replace <code>Includes</code> - with <code>IncludesNOEXEC</code> in the <code class="directive"><a href="../mod/core.html#options">Options</a></code> directive. Note that users may - still use <code><--#include virtual="..." --></code> to execute CGI - scripts if these scripts are in directories designated by a <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code> directive.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="cgi" id="cgi">CGI in General</a></h2> - - - - <p>First of all, you always have to remember that you must trust the - writers of the CGI scripts/programs or your ability to spot potential - security holes in CGI, whether they were deliberate or accidental. CGI - scripts can run essentially arbitrary commands on your system with the - permissions of the web server user and can therefore be extremely - dangerous if they are not carefully checked.</p> - - <p>All the CGI scripts will run as the same user, so they have potential - to conflict (accidentally or deliberately) with other scripts e.g. User - A hates User B, so he writes a script to trash User B's CGI database. One - program which can be used to allow scripts to run as different users is - <a href="../suexec.html">suEXEC</a> which is included with Apache as of - 1.2 and is called from special hooks in the Apache server code. Another - popular way of doing this is with - <a href="http://cgiwrap.unixtools.org/">CGIWrap</a>.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="nsaliasedcgi" id="nsaliasedcgi">Non Script Aliased CGI</a></h2> - - - - <p>Allowing users to execute CGI scripts in any directory should only be - considered if:</p> - - <ul> - <li>You trust your users not to write scripts which will deliberately - or accidentally expose your system to an attack.</li> - <li>You consider security at your site to be so feeble in other areas, - as to make one more potential hole irrelevant.</li> - <li>You have no users, and nobody ever visits your server.</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="saliasedcgi" id="saliasedcgi">Script Aliased CGI</a></h2> - - - - <p>Limiting CGI to special directories gives the admin control over what - goes into those directories. This is inevitably more secure than non - script aliased CGI, but only if users with write access to the - directories are trusted or the admin is willing to test each - new CGI script/program for potential security holes.</p> - - <p>Most sites choose this option over the non script aliased CGI - approach.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="dynamic" id="dynamic">Other sources of dynamic content</a></h2> - - - - <p>Embedded scripting options which run as part of the server itself, - such as <code>mod_php</code>, <code>mod_perl</code>, <code>mod_tcl</code>, - and <code>mod_python</code>, run under the identity of the server itself - (see the <code class="directive"><a href="../mod/mpm_common.html#user">User</a></code> directive), and - therefore scripts executed by these engines potentially can access - anything the server user can. Some scripting engines may provide - restrictions, but it is better to be safe and assume not.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="systemsettings" id="systemsettings">Protecting System Settings</a></h2> - - - - <p>To run a really tight ship, you'll want to stop users from setting - up <code>.htaccess</code> files which can override security features - you've configured. Here's one way to do it.</p> - - <p>In the server configuration file, put</p> - - <div class="example"><p><code> - <Directory /> <br /> - AllowOverride None <br /> - </Directory> - </code></p></div> - - <p>This prevents the use of <code>.htaccess</code> files in all - directories apart from those specifically enabled.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="protectserverfiles" id="protectserverfiles">Protect Server Files by Default</a></h2> - - - - <p>One aspect of Apache which is occasionally misunderstood is the - feature of default access. That is, unless you take steps to change it, - if the server can find its way to a file through normal URL mapping - rules, it can serve it to clients.</p> - - <p>For instance, consider the following example:</p> - - <div class="example"><p><code> - # cd /; ln -s / public_html <br /> - Accessing <code>http://localhost/~root/</code> - </code></p></div> - - <p>This would allow clients to walk through the entire filesystem. To - work around this, add the following block to your server's - configuration:</p> - - <div class="example"><p><code> - <Directory /> <br /> - Order Deny,Allow <br /> - Deny from all <br /> - </Directory> - </code></p></div> - - <p>This will forbid default access to filesystem locations. Add - appropriate <code class="directive"><a href="../mod/core.html#directory">Directory</a></code> blocks to - allow access only in those areas you wish. For example,</p> - - <div class="example"><p><code> - <Directory /usr/users/*/public_html> <br /> - Order Deny,Allow <br /> - Allow from all <br /> - </Directory> <br /> - <Directory /usr/local/httpd> <br /> - Order Deny,Allow <br /> - Allow from all <br /> - </Directory> - </code></p></div> - - <p>Pay particular attention to the interactions of <code class="directive"><a href="../mod/core.html#location">Location</a></code> and <code class="directive"><a href="../mod/core.html#directory">Directory</a></code> directives; for instance, even - if <code><Directory /></code> denies access, a <code> - <Location /></code> directive might overturn it.</p> - - <p>Also be wary of playing games with the <code class="directive"><a href="../mod/mod_userdir.html#userdir">UserDir</a></code> directive; setting it to - something like <code>./</code> would have the same effect, for root, as - the first example above. If you are using Apache 1.3 or above, we strongly - recommend that you include the following line in your server - configuration files:</p> - - <div class="example"><p><code> - UserDir disabled root - </code></p></div> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="watchyourlogs" id="watchyourlogs">Watching Your Logs</a></h2> - - - - <p>To keep up-to-date with what is actually going on against your server - you have to check the <a href="../logs.html">Log Files</a>. Even though - the log files only reports what has already happened, they will give you - some understanding of what attacks is thrown against the server and - allow you to check if the necessary level of security is present.</p> - - <p>A couple of examples:</p> - - <div class="example"><p><code> - grep -c "/jsp/source.jsp?/jsp/ /jsp/source.jsp??" access_log <br /> - grep "client denied" error_log | tail -n 10 - </code></p></div> - - <p>The first example will list the number of attacks trying to exploit the - <a href="http://online.securityfocus.com/bid/4876/info/">Apache Tomcat - Source.JSP Malformed Request Information Disclosure Vulnerability</a>, - the second example will list the ten last denied clients, for example:</p> - - <div class="example"><p><code> - [Thu Jul 11 17:18:39 2002] [error] [client foo.bar.com] client denied - by server configuration: /usr/local/apache/htdocs/.htpasswd - </code></p></div> - - <p>As you can see, the log files only report what already has happened, so - if the client had been able to access the <code>.htpasswd</code> file you - would have seen something similar to:</p> - - <div class="example"><p><code> - foo.bar.com - - [12/Jul/2002:01:59:13 +0200] "GET /.htpasswd HTTP/1.1" - </code></p></div> - - <p>in your <a href="../logs.html#accesslog">Access Log</a>. This means - you probably commented out the following in your server configuration - file:</p> - - <div class="example"><p><code> - <Files ~ "^\.ht"> <br /> - Order allow,deny <br /> - Deny from all <br /> - </Files> - </code></p></div> - - </div></div> -<div class="bottomlang"> -<p><span>Available Languages: </span><a href="../en/misc/security_tips.html" title="English"> en </a> | -<a href="../ko/misc/security_tips.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> | -<a href="../tr/misc/security_tips.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p> -</div><div id="footer"> -<p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p> -<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></div> -</body></html>
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