GuidesSuexec and Apache: A Tutorial Page 4

Suexec and Apache: A Tutorial Page 4




The default value for this option is
PREFIX/share/htdocs, where ‘PREFIX’ comes from the value of the
--prefix option, explicit or implied.

--suexec-gidmin=gid
Another one of suexec‘s restrictions is that the user it’s
being asked to execute the script as mustn’t be considered ‘privileged.’ On
Linux and other Unix-like systems this generally means that it mustn’t be the
root user, but suexec takes this a step further and
will refuse to execute as any user with a group ID less than the value of this
option.

The default value for this option, if not specified, is
100.

--suexec-logfile=filename
This specifies the name of the file to which the wrapper will report
errors and successful invocations. It is opened and accessed as
root, but closed before control is passed to the script.

The
default for this option is PREFIX/var/log/suexec_log, where
‘PREFIX’ is the value from the --prefix option.

--suexec-safepath=path-list
Not only is the list of environment variables examined and sanitized before
the script is invoked, but the default PATH is set to a known list
of directories as well. This list is hard-coded at compile-time, and is defined
by this option.

The default value for --suexec-safepath is
/usr/local/bin:/usr/bin:/bin.

--suexec-uidmin=uid
As with the --suexec-gidmin option described earlier, this
option is used to inform suexec of forbidden UID values. If a
request is made that would result in the execution of a script by a user with a
UID equal to or less than this value, the wrapper will log the fact and not
process the request. This foils things like a request for
~root/script.

The default value for this option is
100.

--suexec-umask=octal-umask
This option defines the default permission mode to be applied to files
created by the script (if it doesn’t explicitly set them itself). The umask is
specified as a three-digit octal number indicating which permission bits should
not be set; see the description of the umask(1) command for
more details.

If this option isn’t defined at compile-time, at run-time the
suexec wrapper will inherit the umask setting from the parent
Apache server process.

--suexec-userdir=path
This option specifies the subdirectory underneath a user’s home directory
that suexec will use to find scripts for
~username-style URLs. This needs to match the setting of the
UserDir directive in your server configuration files.

Note:
suexec can only handle simple subdirectory expressions.
The
more complex pattern-handling capabilities of the mod_userdir
module (which implements the UserDir directive) cannot be used
with the suexec wrapper.

The default --suexec-userdir setting is
public_html.

If you want to change the location of the suexec binary, you
can do so by adding a new definition of SUEXEC_BIN to the
compilation flags:

    % env CFLAGS="-Wall -DSUEXEC_BIN="/usr/local/web/apache/suexec"" 
    >  ./configure --enable-suexec ...
  

You should be extremely cautious about changing other definitions, such as
HTTPD_ROOT, however, since suexec isn't the only part
of Apache that uses them.

User IDs Suexec Will Use

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