<P ALIGN="LEFT">
<OL>
- <LH><BIG><STRONG>CONTENTS</STRONG></BIG></LH>
- <LI><A HREF="#what">What is suEXEC?</A></LI>
- <LI><A HREF="#before">Before we begin.</A></LI>
- <LI><A HREF="#model">suEXEC Security Model.</A></LI>
- <LI><A HREF="#install">Configuring & Installing suEXEC</A></LI>
- <LI><A HREF="#enable">Enabling & Disabling suEXEC</A></LI>
- <LI><A HREF="#debug">Debugging suEXEC</A></LI>
- <LI><A HREF="#jabberwock">Beware the Jabberwock: Warnings & Examples</A></LI>
+ <LH><BIG><STRONG>CONTENTS</STRONG></BIG></LH>
+ <LI><A HREF="#what">What is suEXEC?</A></LI>
+ <LI><A HREF="#before">Before we begin.</A></LI>
+ <LI><A HREF="#model">suEXEC Security Model.</A></LI>
+ <LI><A HREF="#install">Configuring & Installing suEXEC</A></LI>
+ <LI><A HREF="#enable">Enabling & Disabling suEXEC</A></LI>
+ <LI><A HREF="#debug">Debugging suEXEC</A></LI>
+ <LI><A HREF="#jabberwock">Beware the Jabberwock: Warnings &
+ Examples</A></LI>
</OL>
</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:
- <OL>
- <LI><STRONG>Was the wrapper called with the proper number of arguments?</STRONG>
- <BLOCKQUOTE>
- 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.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the user executing this wrapper a valid user of this system?</STRONG>
- <BLOCKQUOTE>
- This is to ensure that the user executing the wrapper is truly a user of the system.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is this valid user allowed to run the wrapper?</STRONG>
- <BLOCKQUOTE>
- Is this user the user allowed to run this wrapper? Only one user (the Apache
- user) is allowed to execute this program.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Does the target program have an unsafe hierarchical reference?</STRONG>
- <BLOCKQUOTE>
- Does the target program contain a leading '/' or have a '..' backreference? These
- are not allowed; the target program must reside within the Apache webspace.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the target user name valid?</STRONG>
- <BLOCKQUOTE>
- Does the target user exist?
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the target group name valid?</STRONG>
- <BLOCKQUOTE>
- Does the target group exist?
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the target user <EM>NOT</EM> superuser?</STRONG>
- <BLOCKQUOTE>
- Presently, suEXEC does not allow 'root' to execute CGI/SSI programs.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the target userid <EM>ABOVE</EM> the minimum ID number?</STRONG>
- <BLOCKQUOTE>
- 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.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the target group <EM>NOT</EM> the superuser group?</STRONG>
- <BLOCKQUOTE>
- Presently, suEXEC does not allow the 'root' group to execute CGI/SSI programs.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the target groupid <EM>ABOVE</EM> the minimum ID number?</STRONG>
- <BLOCKQUOTE>
- 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.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Can the wrapper successfully become the target user and group?</STRONG>
- <BLOCKQUOTE>
- 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.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Does the directory in which the program resides exist?</STRONG>
- <BLOCKQUOTE>
- If it doesn't exist, it can't very well contain files.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the directory within the Apache webspace?</STRONG>
- <BLOCKQUOTE>
- If the request is for a regular portion of the server, is the requested directory
- within the server's document root? If the request is for a UserDir, is the requested
- directory within the user's document root?
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the directory <EM>NOT</EM> writable by anyone else?</STRONG>
- <BLOCKQUOTE>
- We don't want to open up the directory to others; only the owner user may be able
- to alter this directories contents.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Does the target program exist?</STRONG>
- <BLOCKQUOTE>
- If it doesn't exists, it can't very well be executed.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the target program <EM>NOT</EM> writable by anyone else?</STRONG>
- <BLOCKQUOTE>
- We don't want to give anyone other than the owner the ability to change the program.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the target program <EM>NOT</EM> setuid or setgid?</STRONG>
- <BLOCKQUOTE>
- We do not want to execute programs that will then change our UID/GID again.
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Is the target user/group the same as the program's user/group?</STRONG>
- <BLOCKQUOTE>
- Is the user the owner of the file?
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Can we successfully clean the process environment to ensure safe operations?</STRONG>
- <BLOCKQUOTE>
- suEXEC cleans the process' environment by establishing a safe execution PATH (defined
- during configuration), as well as only passing through those variables whose names
- are listed in the safe environment list (also created during configuration).
- </BLOCKQUOTE>
- </LI>
- <LI><STRONG>Can we successfully become the target program and execute?</STRONG>
- <BLOCKQUOTE>
- Here is where suEXEC ends and the target program begins.
- </BLOCKQUOTE>
- </LI>
- </OL>
+ <LI><STRONG>Was the wrapper called with the proper number of arguments?</STRONG>
+ 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.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the user executing this wrapper a valid user of this system?</STRONG>
+ This is to ensure that the user executing the wrapper is truly a user of the system.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is this valid user allowed to run the wrapper?</STRONG>
+ Is this user the user allowed to run this wrapper? Only one user (the Apache
+ user) is allowed to execute this program.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Does the target program have an unsafe hierarchical reference?</STRONG>
+ Does the target program contain a leading '/' or have a '..' backreference? These
+ are not allowed; the target program must reside within the Apache webspace.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the target user name valid?</STRONG>
+ Does the target user exist?
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the target group name valid?</STRONG>
+ Does the target group exist?
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the target user <EM>NOT</EM> superuser?</STRONG>
+ Presently, suEXEC does not allow 'root' to execute CGI/SSI programs.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the target userid <EM>ABOVE</EM> the minimum ID number?</STRONG>
+ 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.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the target group <EM>NOT</EM> the superuser group?</STRONG>
+ Presently, suEXEC does not allow the 'root' group to execute CGI/SSI programs.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the target groupid <EM>ABOVE</EM> the minimum ID number?</STRONG>
+ 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.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Can the wrapper successfully become the target user and group?</STRONG>
+ 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.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Does the directory in which the program resides exist?</STRONG>
+ If it doesn't exist, it can't very well contain files.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the directory within the Apache webspace?</STRONG>
+ If the request is for a regular portion of the server, is the requested directory
+ within the server's document root? If the request is for a UserDir, is the requested
+ directory within the user's document root?
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the directory <EM>NOT</EM> writable by anyone else?</STRONG>
+ We don't want to open up the directory to others; only the owner user may be able
+ to alter this directories contents.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Does the target program exist?</STRONG>
+ If it doesn't exists, it can't very well be executed.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the target program <EM>NOT</EM> writable by anyone else?</STRONG>
+ We don't want to give anyone other than the owner the ability to change the program.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the target program <EM>NOT</EM> setuid or setgid?</STRONG>
+ We do not want to execute programs that will then change our UID/GID again.
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Is the target user/group the same as the program's user/group?</STRONG>
+ Is the user the owner of the file?
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Can we successfully clean the process environment to ensure safe operations?</STRONG>
+ suEXEC cleans the process' environment by establishing a safe execution PATH (defined
+ during configuration), as well as only passing through those variables whose names
+ are listed in the safe environment list (also created during configuration).
+ </BLOCKQUOTE>
+ </LI>
+ <LI><STRONG>Can we successfully become the target program and execute?</STRONG>
+ Here is where suEXEC ends and the target program begins.
+ </BLOCKQUOTE>
+ </LI>
+ </OL>
</P>
<P ALIGN="LEFT">
<STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
</P>
-<H3><A NAME="install">Configuring & Installing suEXEC</A></H3>
+<H3><A NAME="install">Configuring & Installing suEXEC</A></H3>
<P ALIGN="LEFT">
Here's where we begin the fun. The configuration and installation of suEXEC is
a four step process: edit the suEXEC header file, compile suEXEC, place the
<STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
</P>
-<H3><A NAME="enable">Enabling & Disabling suEXEC</A></H3>
+<H3><A NAME="enable">Enabling & Disabling suEXEC</A></H3>
<P ALIGN="LEFT">
After properly installing the <STRONG>suexec</STRONG> wrapper
executable, you must kill and restart the Apache server. A simple
<STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
</P>
-<H3><A NAME="jabberwock">Beware the Jabberwock: Warnings & Examples</A></H3>
+<H3><A NAME="jabberwock">Beware the Jabberwock: Warnings & Examples</A></H3>
<P ALIGN="LEFT">
<STRONG>NOTE!</STRONG> This section may not be complete. For the latest
revision of this section of the documentation, see the Apache Group's
limitations on server setup. Please review these before submitting any
"bugs" regarding suEXEC.
<UL>
- <LH><STRONG>suEXEC Points Of Interest</STRONG></LH>
- <LI>Hierarchy limitations
- <BLOCKQUOTE>
- For security and efficiency reasons, all suexec requests must
- remain within either a top-level document root for virtual
- host requests, or one top-level personal document root for
- userdir requests. For example, if you have four VirtualHosts
- configured, you would need to structure all of your VHosts'
- document roots off of one main Apache document hierarchy to
- take advantage of suEXEC for VirtualHosts. (Example forthcoming.)
- </BLOCKQUOTE>
- </LI>
- <LI>suEXEC's PATH environment variable
- <BLOCKQUOTE>
- This can be a dangerous thing to change. Make certain every
- path you include in this define is a <STRONG>trusted</STRONG>
- directory. You don't want to open people up to having someone
- from across the world running a trojan horse on them.
- </BLOCKQUOTE>
- </LI>
- <LI>Altering the suEXEC code
- <BLOCKQUOTE>
- Again, this can cause <STRONG>Big Trouble</STRONG> if you try
- this without knowing what you are doing. Stay away from it
- if at all possible.
- </BLOCKQUOTE>
- </LI>
+ <LH><STRONG>suEXEC Points Of Interest</STRONG></LH>
+ <LI>Hierarchy limitations
+ For security and efficiency reasons, all suexec requests must
+ remain within either a top-level document root for virtual
+ host requests, or one top-level personal document root for
+ userdir requests. For example, if you have four VirtualHosts
+ configured, you would need to structure all of your VHosts'
+ document roots off of one main Apache document hierarchy to
+ take advantage of suEXEC for VirtualHosts. (Example forthcoming.)
+ </BLOCKQUOTE>
+ </LI>
+ <LI>suEXEC's PATH environment variable
+ This can be a dangerous thing to change. Make certain every
+ path you include in this define is a <STRONG>trusted</STRONG>
+ directory. You don't want to open people up to having someone
+ from across the world running a trojan horse on them.
+ </BLOCKQUOTE>
+ </LI>
+ <LI>Altering the suEXEC code
+ Again, this can cause <STRONG>Big Trouble</STRONG> if you try
+ this without knowing what you are doing. Stay away from it
+ if at all possible.
+ </BLOCKQUOTE>
+ </LI>
</UL>
<P ALIGN="CENTER">
projects / thirdparty / apache / httpd.git / commitdiff
