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From nil...@apache.org
Subject svn commit: r686267 - /httpd/httpd/trunk/docs/manual/misc/security_tips.xml
Date Fri, 15 Aug 2008 16:00:48 GMT
Author: nilgun
Date: Fri Aug 15 09:00:48 2008
New Revision: 686267

URL: http://svn.apache.org/viewvc?rev=686267&view=rev
Log:
pre-translation improvements

Modified:
    httpd/httpd/trunk/docs/manual/misc/security_tips.xml

Modified: httpd/httpd/trunk/docs/manual/misc/security_tips.xml
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/docs/manual/misc/security_tips.xml?rev=686267&r1=686266&r2=686267&view=diff
==============================================================================
--- httpd/httpd/trunk/docs/manual/misc/security_tips.xml (original)
+++ httpd/httpd/trunk/docs/manual/misc/security_tips.xml Fri Aug 15 09:00:48 2008
@@ -24,12 +24,12 @@
   <parentdocument href="./">Miscellaneous Documentation</parentdocument>
 
   <title>Security Tips</title>
-  
+
   <summary>
-    <p>Some hints and tips on security issues in setting up a web server. 
+    <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>
   </summary>
-  
+
   <section id="uptodate"><title>Keep up to Date</title>
 
     <p>The Apache HTTP Server has a good record for security and a
@@ -89,7 +89,7 @@
       <li>The values of various timeout-related directives provided by
       other modules should be checked.</li>
 
-      <li>The directives 
+      <li>The directives
       <directive module="core">LimitRequestBody</directive>,
       <directive module="core">LimitRequestFields</directive>,
       <directive module="core">LimitRequestFieldSize</directive>,
@@ -113,12 +113,12 @@
 
       <li>The use of a threaded <a href="../mpm.html">mpm</a> may
       allow you to handle more simultaneous connections, thereby
-      mitigating DoS attacks.  Further, the experimental 
+      mitigating DoS attacks.  Further, the experimental
       <module>event</module> mpm
       uses asynchronous processing to avoid devoting a thread to each
       connection. At the current point of time this
       is work in progress and not fully implemented.  Especially the
-      <module>event</module> mpm is currently incompatible with 
+      <module>event</module> mpm is currently incompatible with
       <module>mod_ssl</module> and other input filters.</li>
 
       <li>There are a number of third-party modules available through
@@ -126,26 +126,26 @@
       href="http://modules.apache.org/">http://modules.apache.org/</a>
       that can restrict certain client behaviors and thereby mitigate
       DoS problems.</li>
-     
+
     </ul>
 
   </section>
-    
+
 
   <section id="serverroot">
-  
+
     <title>Permissions on ServerRoot Directories</title>
-    
-    <p>In typical operation, Apache is started by the root user, and it 
-    switches to the user defined by the <directive 
-    module="mpm_common">User</directive> 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  /usr/local/apache then it is suggested that you create 
-    that directory as root, with commands like these:</p>
-    
+
+    <p>In typical operation, Apache is started by the root user, and it
+    switches to the user defined by the <directive
+    module="mpm_common">User</directive> 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>
+
     <example>
       mkdir /usr/local/apache <br />
       cd /usr/local/apache <br />
@@ -154,196 +154,197 @@
       chgrp 0 . bin conf logs <br />
       chmod 755 . bin conf logs
     </example>
-    
-    <p>It is assumed that /, /usr, and /usr/local are only modifiable by 
-    root. When you install the <program>httpd</program> executable, you
-    should ensure that it is similarly protected:</p>
-    
+
+    <p>It is assumed that <code>/</code>, <code>/usr</code>,
and
+    <code>/usr/local</code> are only modifiable by root. When you install the
+    <program>httpd</program> executable, you should ensure that it is
+    similarly protected:</p>
+
     <example>
       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
     </example>
-    
-    <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 
+
+    <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. 
+
+    <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 <program>httpd</program> 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 
+    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>
-    
+
   </section>
-  
+
   <section id="ssi">
-  
+
     <title>Server Side Includes</title>
-    
-    <p>Server Side Includes (SSI) present a server administrator with 
+
+    <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 
+
+    <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 "exec cmd" 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 httpd.conf.</p>
-    
-    <p>There are ways to enhance the security of SSI files while still 
+
+    <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 
+
+    <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 .html or .htm 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 .shtml. 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 
+
+    <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 <directive
-    module="core">Options</directive> directive.  Note that users may 
-    still use &lt;--#include virtual="..." --&gt; to execute CGI scripts if 
-    these scripts are in directories designated by a <directive
+    module="core">Options</directive> directive.  Note that users may
+    still use <code>&lt;--#include virtual="..." --&gt;</code> to execute
CGI
+    scripts if these scripts are in directories designated by a <directive
     module="mod_alias">ScriptAlias</directive> directive.</p>
-    
+
   </section>
-  
+
   <section id="cgi">
-  
+
     <title>CGI in General</title>
-    
-    <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 
+
+    <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 
+
+    <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="../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>
-    
+
   </section>
 
   <section id="nsaliasedcgi">
-  
+
     <title>Non Script Aliased CGI</title>
-    
-    <p>Allowing users to execute CGI scripts in any directory should only be 
+
+    <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 
+      <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, 
+      <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>
-    
+
   </section>
-  
+
   <section id="saliasedcgi">
-  
+
     <title>Script Aliased CGI</title>
-    
-    <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 
+
+    <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 
+
+    <p>Most sites choose this option over the non script aliased CGI
     approach.</p>
-    
+
   </section>
 
    <section id="dynamic">
 
   <title>Other sources of dynamic content</title>
 
-  <p>
-  Embedded scripting options which run as part of the server itself,
-  such as mod_php, mod_perl, mod_tcl, and mod_python, run under the
-  identity of the server itself (see the <directive 
-  module="mpm_common">User</directive> directive), and therefore
-  scripts executed by these engines potentially can access anything the
-  server user can. Some scripting engines may provide restrictions, but
+  <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 <directive module="mpm_common">User</directive> 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>
 
   </section>
-  
+
   <section id="systemsettings">
-  
+
     <title>Protecting System Settings</title>
-    
-    <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 
+
+    <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>
-    
+
     <example>
       &lt;Directory /&gt; <br />
         AllowOverride None <br />
       &lt;/Directory&gt;
     </example>
-    
-    <p>This prevents the use of <code>.htaccess</code> files in all 
+
+    <p>This prevents the use of <code>.htaccess</code> files in all
     directories apart from those specifically enabled.</p>
-    
+
   </section>
-  
+
   <section id="protectserverfiles">
-  
+
     <title>Protect Server Files by Default</title>
-    
-    <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 
+
+    <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>
-    
+
     <example>
       # cd /; ln -s / public_html <br />
       Accessing <code>http://localhost/~root/</code>
     </example>
-    
-    <p>This would allow clients to walk through the entire filesystem. To 
-    work around this, add the following block to your server's 
+
+    <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>
-    
+
     <example>
       &lt;Directory /&gt; <br />
       Order Deny,Allow <br />
       Deny from all <br />
       &lt;/Directory&gt;
     </example>
-    
-    <p>This will forbid default access to filesystem locations. Add 
-    appropriate <directive module="core">Directory</directive> blocks to 
+
+    <p>This will forbid default access to filesystem locations. Add
+    appropriate <directive module="core">Directory</directive> blocks to
     allow access only in those areas you wish. For example,</p>
-    
+
     <example>
       &lt;Directory /usr/users/*/public_html&gt; <br />
         Order Deny,Allow <br />
@@ -354,72 +355,72 @@
         Allow from all <br />
       &lt;/Directory&gt;
     </example>
-    
+
     <p>Pay particular attention to the interactions of <directive
-    module="core">Location</directive> and <directive 
-    module="core">Directory</directive> directives; for instance, even 
+    module="core">Location</directive> and <directive
+    module="core">Directory</directive> directives; for instance, even
     if <code>&lt;Directory /&gt;</code> denies access, a <code>
     &lt;Location /&gt;</code> directive might overturn it.</p>
-    
+
     <p>Also be wary of playing games with the <directive
-    module="mod_userdir">UserDir</directive> directive; setting it to 
-    something like "./" 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 
+    module="mod_userdir">UserDir</directive> 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>
-    
+
     <example>
       UserDir disabled root
     </example>
-    
+
   </section>
-  
+
   <section id="watchyourlogs">
-  
+
     <title>Watching Your Logs</title>
-    
-    <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 
+
+    <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>
-    
+
     <example>
       grep -c "/jsp/source.jsp?/jsp/ /jsp/source.jsp??" access_log <br />
       grep "client denied" error_log | tail -n 10
     </example>
-    
+
     <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>, 
+    <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>
-    
+
     <example>
-      [Thu Jul 11 17:18:39 2002] [error] [client foo.example.com] client denied 
+      [Thu Jul 11 17:18:39 2002] [error] [client foo.example.com] client denied
       by server configuration: /usr/local/apache/htdocs/.htpasswd
     </example>
-    
-    <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

+
+    <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>
-    
+
     <example>
       foo.example.com - - [12/Jul/2002:01:59:13 +0200] "GET /.htpasswd HTTP/1.1"
     </example>
-    
-    <p>in your <a href="../logs.html#accesslog">Access Log</a>. This means

-    you probably commented out the following in your server configuration 
+
+    <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>
-    
+
     <example>
       &lt;Files ~ "^\.ht"&gt; <br />
         Order allow,deny <br />
         Deny from all <br />
       &lt;/Files&gt;
     </example>
-    
+
   </section>
-  
+
 </manualpage>



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