manual/mod/mod_privileges.xml

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<modulesynopsis metafile="mod_privileges.xml.meta">

<name>mod_privileges</name>
<description>Support for Solaris privileges and for running virtual hosts
under different user IDs.</description>
<status>Experimental</status>
<identifier>privileges_module</identifier>
<compatibility>Available in Apache 2.3 and up, on Solaris 10 and
OpenSolaris platforms</compatibility>

<summary>
<p>This module enables different Virtual Hosts to run with different
Unix&trade; <var>User</var> and <var>Group</var> IDs, and with different
<a href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
>Solaris Privileges</a>.  In particular, it offers a solution to the
problem of privilege separation between different Virtual Hosts, first
promised by the abandoned perchild MPM.  It also offers other security
enhancements.</p>

<p>Unlike perchild, <module>mod_privileges</module>
is not itself an MPM.  It works <em>within</em> a processing model to
set privileges and User/Group <em>per request</em> in a running process.
It is therefore not compatible with a threaded MPM, and will refuse
to run under one.</p>

<p><module>mod_privileges</module> raises security issues similar to
those of <a href="../suexec.html">suexec</a>.  But unlike suexec,
it applies not only to CGI programs but to the entire request processing
cycle, including in-process applications and subprocesses.
It is ideally suited to running PHP applications under <strong>mod_php</strong>,
which is also incompatible with threaded MPMs.  It is also well-suited
to other in-process scripting applications such as <strong>mod_perl</strong>,
<strong>mod_python</strong>, and <strong>mod_ruby</strong>, and to
applications implemented in C as apache modules where privilege
separation is an issue.</p>

</summary>

<section id="security"><title>Security Considerations</title>

<p><module>mod_privileges</module> introduces new security concerns
in situations where <strong>untrusted code</strong> may be run
<strong>within the webserver process</strong>.  This applies to
untrusted modules, and scripts running under modules such as
mod_php or mod_perl.  Scripts running externally (e.g. as CGI
or in an appserver behind mod_proxy or mod_jk) are NOT affected.</p>

<p>The basic security concerns with mod_privileges are:</p>
<ul><li>Running as a system user introduces the same security issues
    as mod_suexec, and near-equivalents such as cgiwrap and suphp.</li>
<li>A privileges-aware malicious user extension (module or script)
    could escalate its privileges to anything available to the
    httpd process in any virtual host.  This introduces new risks
    if (and only if) mod_privileges is compiled with the
    <var>BIG_SECURITY_HOLE</var> option.</li>
<li>A privileges-aware malicious user extension (module or script)
    could escalate privileges to set its user ID to another system
    user (and/or group).</li>
</ul>

<p>The <directive>PrivilegesMode</directive> directive allows you to
select either <var>FAST</var> or <var>SECURE</var> mode.  You can
mix modes, using <var>FAST</var> mode for trusted users and
fully-audited code paths, while imposing SECURE mode where an
untrusted user has scope to introduce code.</p>
<p>Before describing the modes, we should also introduce the target
use cases: Benign vs Hostile.  In a benign situation, you want to
separate users for their convenience, and protect them and the server
against the risks posed by honest mistakes, but you trust your users
are not deliberately subverting system security.  In a hostile
situation - e.g. commercial hosting - you may have users deliberately
attacking the system or each other.</p>
<dl>
<dt>FAST mode</dt>
<dd>In <var>FAST</var> mode, requests are run in-process with the
selected uid/gid and privileges, so the overhead is negligible.
This is suitable for benign situations, but is not secure against an
attacker escalating privileges with an in-process module or script.</dd>
<dt>SECURE mode</dt>
<dd>A request in <var>SECURE</var> mode forks a subprocess, which
then drops privileges.  This is a very similar case to running CGI
with suexec, but for the entire request cycle, and with the benefit
of fine-grained control of privileges.</dd>
</dl>
<p>You can select different <directive>PrivilegesMode</directive>s for
each virtual host, and even in a directory context within a virtual
host.  <var>FAST</var> mode is appropriate where the user(s) are
trusted and/or have no privilege to load in-process code.
<var>SECURE</var> mode is appropriate to cases where untrusted code
might be run in-process.  However, even in <var>SECURE</var> mode,
there is no protection against a malicious user who is able to
introduce privileges-aware code running <em>before the start of the
request-processing cycle.</em></p>

</section>
<directivesynopsis>
<name>PrivilegesMode</name>
<description>Trade off processing speed and efficiency vs security against
malicious privileges-aware code.</description>
<syntax>PrivilegesMode FAST|SECURE|SELECTIVE</syntax>
<contextlist>
	<context>server config</context>
	<context>virtual host</context>
	<context>directory</context>
</contextlist>
<compatibility>Available on Solaris 10 and OpenSolaris with
non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>
<usage><p>This directive trades off performance vs security against
malicious, privileges-aware code.  In <var>SECURE</var> mode, each request
runs in a secure subprocess, incurring a substantial performance penalty.
In <var>FAST</var> mode, the server is not protected against escalation
of privileges as discussed above.</p>
<p>This directive differs slightly between a <code>&lt;Directory&gt;</code>
	context (including equivalents such as Location/Files/If) and a
	top-level or <code>&lt;VirtualHost&gt;</code>.</p>
<p>At top-level, it sets a default that will be inherited by virtualhosts.
	In a virtual host, FAST or SECURE mode acts on the entire
	HTTP request, and any settings in a <code>&lt;Directory&gt;</code>
	context will be <strong>ignored</strong>.  A third pseudo-mode
	SELECTIVE defers the choice of FAST vs SECURE to directives in a
	<code>&lt;Directory&gt;</code> context.</p>
<p>In a <code>&lt;Directory&gt;</code> context, it is applicable only
	where SELECTIVE mode was set for the VirtualHost.  Only
	FAST or SECURE can be set in this context (SELECTIVE would be
meaningless).</p>
<note type="warning"><title>Warning</title>
	Where SELECTIVE mode is selected for a virtual host, the activation
	of privileges must be deferred until <em>after</em> the mapping
	phase of request processing has determined what
	<code>&lt;Directory&gt;</code> context applies to the request.
	This might give an attacker opportunities to introduce
	code through a <directive module="mod_rewrite">RewriteMap</directive>
	running at top-level or <code>&lt;VirtualHost&gt;</code> context
	<em>before</em> privileges have been dropped and userid/gid set.
</note>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>VHostUser</name>
<description>Sets the User ID under which a virtual host runs.</description>
<syntax>VHostUser <var>unix-userid</var></syntax>
<default>Inherits the userid specified in
<directive module="mod_unixd">User</directive></default>
<contextlist><context>virtual host</context></contextlist>
<compatibility>Available on Solaris 10 and OpenSolaris with
non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>

<usage>
    <p>The <directive>VHostUser</directive> directive sets the Unix userid
    under which the server will process requests to a virtualhost.
    The userid is set before the request is processed and reset afterwards
    using <a
    href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
    >Solaris Privileges</a>.  Since the setting applies to the
    <em>process</em>, this is not compatible with threaded MPMs.</p>
    <p><var>Unix-userid</var> is one of:</p>
    <dl>
      <dt>A username</dt>
      <dd>Refers to the given user by name.</dd>

      <dt><code>#</code> followed by a user number.</dt>
      <dd>Refers to a user by its number.</dd>
    </dl>

    <note type="warning"><title>Security</title>
    <p>This directive cannot be used to run apache as root!
    Nevertheless, it opens potential security issues similar to
    those discussed in the <a href="../suexec.html">suexec</a>
    documentation.</p></note>
</usage>
<seealso><directive module="mod_unixd">User</directive></seealso>
<seealso><directive module="mod_suexec">SuexecUserGroup</directive></seealso>
</directivesynopsis>

<directivesynopsis>
<name>VHostGroup</name>
<description>Sets the Group ID under which a virtual host runs.</description>
<syntax>VHostGroup <var>unix-groupid</var></syntax>
<default>Inherits the group id specified in
<directive module="mod_unixd">Group</directive></default>
<contextlist><context>virtual host</context></contextlist>
<compatibility>Available on Solaris 10 and OpenSolaris with
non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>

<usage>
    <p>The <directive>VHostGroup</directive> directive sets the Unix group
    under which the server will process requests to a virtualhost.
    The group is set before the request is processed and reset afterwards
    using <a
    href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
    >Solaris Privileges</a>.  Since the setting applies to the
    <em>process</em>, this is not compatible with threaded MPMs.</p>
    <p><var>Unix-group</var> is one of:</p>
    <dl>
      <dt>A group name</dt>
      <dd>Refers to the given group by name.</dd>

      <dt><code>#</code> followed by a group number.</dt>
      <dd>Refers to a group by its number.</dd>
    </dl>

    <note type="warning"><title>Security</title>
    <p>This directive cannot be used to run apache as root!
    Nevertheless, it opens potential security issues similar to
    those discussed in the <a href="../suexec.html">suexec</a>
    documentation.</p></note>
</usage>
<seealso><directive module="mod_unixd">Group</directive></seealso>
<seealso><directive module="mod_suexec">SuexecUserGroup</directive></seealso>
</directivesynopsis>

<directivesynopsis>
<name>VHostSecure</name>
<description>Determines whether the server runs with enhanced security
for the virtualhost.</description>
<syntax>VHostSecure On|Off</syntax>
<default>VHostSecure On</default>
<contextlist><context>virtual host</context></contextlist>
<compatibility>Available on Solaris 10 and OpenSolaris with
non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>

<usage>
    <p>Determines whether the virtual host processes requests with
    security enhanced by removal of <a
    href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
    >Privileges</a> that are rarely needed in a webserver, but which are
    available by default to a normal Unix user and may therefore
    be required by modules and applications.  It is recommended that
    you retain the default (On) unless it prevents an application running.
    Since the setting applies to the <em>process</em>, this is not
    compatible with threaded MPMs.</p>
    <note><title>Note</title>
    <p>If <directive>VHostSecure</directive> prevents an application
    running, this may be a warning sign that the application should be
    reviewed for security.</p></note>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>VHostCGIMode</name>
<description>Determines whether the virtualhost can run
subprocesses, and the privileges available to subprocesses.</description>
<syntax>VHostCGIMode On|Off|Secure</syntax>
<default>VHostCGIMode On</default>
<contextlist><context>virtual host</context></contextlist>
<compatibility>Available on Solaris 10 and OpenSolaris with
non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>

<usage>
    <p>Determines whether the virtual host is allowed to run fork and exec,
    the <a
    href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
    >privileges</a> required to run subprocesses.  If this is set to
    <var>Off</var> the virtualhost is denied the privileges and will not
    be able to run traditional CGI programs or scripts under the traditional
    <module>mod_cgi</module>, nor similar external programs such as those
    created by <module>mod_ext_filter</module> or
    <directive module="mod_rewrite">RewriteMap</directive> <var>prog</var>.
    Note that it does not prevent CGI programs running under alternative
    process and security models such as <a href="http://fastcgi.coremail.cn"
    >mod_fcgid</a>, which is a recommended solution in Solaris.</p>
    <p>If set to <var>On</var> or <var>Secure</var>, the virtual host
    is permitted to run external programs and scripts as above.
    Setting <directive>VHostCGIMode</directive> <var>Secure</var> has
    the effect of denying privileges to the subprocesses, as described
    for <directive>VHostSecure</directive>.</p>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>DTracePrivileges</name>
<description>Determines whether the privileges required by dtrace are enabled.</description>
<syntax>DTracePrivileges On|Off</syntax>
<default>DTracePrivileges Off</default>
<contextlist><context>server config</context></contextlist>
<compatibility>Available on Solaris 10 and OpenSolaris with
non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>

<usage>
    <p>This server-wide directive determines whether Apache will run with
    the <a
    href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
    >privileges</a> required to run
    <a href="http://www.sun.com/bigadmin/content/dtrace/">dtrace</a>.
    Note that <var>DTracePrivileges On</var> will not in itself
    activate DTrace, but <var>DTracePrivileges Off</var> will prevent
    it working.</p>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>VHostPrivs</name>
<description>Assign arbitrary privileges to a virtual host.</description>
<syntax>VHostPrivs [+-]?<var>privilege-name</var> [[+-]?privilege-name] ...</syntax>
<default>None</default>
<contextlist><context>virtual host</context></contextlist>
<compatibility>Available on Solaris 10 and OpenSolaris with
non-threaded MPMs (<module>prefork</module> or custom MPM)
and when <module>mod_privileges</module> is compiled with the
<var>BIG_SECURITY_HOLE</var> compile-time option.</compatibility>

<usage>
    <p><directive>VHostPrivs</directive> can be used to assign arbitrary <a
    href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
    >privileges</a> to a virtual host.  Each <var>privilege-name</var>
    is the name of a Solaris privilege, such as <var>file_setid</var>
    or <var>sys_nfs</var>.</p>

    <p>A <var>privilege-name</var> may optionally be prefixed by
    + or -, which will respectively allow or deny a privilege.
    If used with neither + nor -, all privileges otherwise assigned
    to the virtualhost will be denied.  You can use this to override
    any of the default sets and construct your own privilege set.</p>

    <note type="warning"><title>Security</title>
    <p>This directive can open huge security holes in apache, up to
    and including running requests with root-level powers.  Do not
    use it unless you fully understand what you are doing!</p></note>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>VHostCGIPrivs</name>
<description>Assign arbitrary privileges to subprocesses created
by a virtual host.</description>
<syntax>VHostPrivs [+-]?<var>privilege-name</var> [[+-]?privilege-name] ...</syntax>
<default>None</default>
<contextlist><context>virtual host</context></contextlist>
<compatibility>Available on Solaris 10 and OpenSolaris with
non-threaded MPMs (<module>prefork</module> or custom MPM)
and when <module>mod_privileges</module> is compiled with the
<var>BIG_SECURITY_HOLE</var> compile-time option.</compatibility>

<usage>
    <p><directive>VHostCGIPrivs</directive> can be used to assign arbitrary <a
    href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
    >privileges</a> to subprocesses created by a virtual host, as discussed
    under <directive>VHostCGIMode</directive>.  Each <var>privilege-name</var>
    is the name of a Solaris privilege, such as <var>file_setid</var>
    or <var>sys_nfs</var>.</p>

    <p>A <var>privilege-name</var> may optionally be prefixed by
    + or -, which will respectively allow or deny a privilege.
    If used with neither + nor -, all privileges otherwise assigned
    to the virtualhost will be denied.  You can use this to override
    any of the default sets and construct your own privilege set.</p>

    <note type="warning"><title>Security</title>
    <p>This directive can open huge security holes in apache subprocesses,
    up to and including running them with root-level powers.  Do not
    use it unless you fully understand what you are doing!</p></note>
</usage>
</directivesynopsis>


</modulesynopsis>
1	<?xml version="1.0"?>
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22
23	<modulesynopsis metafile="mod_privileges.xml.meta">
24
25	<name>mod_privileges</name>
26	<description>Support for Solaris privileges and for running virtual hosts
27	under different user IDs.</description>
28	<status>Experimental</status>
29	<identifier>privileges_module</identifier>
30	<compatibility>Available in Apache 2.3 and up, on Solaris 10 and
31	OpenSolaris platforms</compatibility>
32
33	<summary>
34	<p>This module enables different Virtual Hosts to run with different
35	Unix™ <var>User</var> and <var>Group</var> IDs, and with different
36	<a href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
37	>Solaris Privileges</a>. In particular, it offers a solution to the
38	problem of privilege separation between different Virtual Hosts, first
39	promised by the abandoned perchild MPM. It also offers other security
40	enhancements.</p>
41
42	<p>Unlike perchild, <module>mod_privileges</module>
43	is not itself an MPM. It works <em>within</em> a processing model to
44	set privileges and User/Group <em>per request</em> in a running process.
45	It is therefore not compatible with a threaded MPM, and will refuse
46	to run under one.</p>
47
48	<p><module>mod_privileges</module> raises security issues similar to
49	those of <a href="../suexec.html">suexec</a>. But unlike suexec,
50	it applies not only to CGI programs but to the entire request processing
51	cycle, including in-process applications and subprocesses.
52	It is ideally suited to running PHP applications under <strong>mod_php</strong>,
53	which is also incompatible with threaded MPMs. It is also well-suited
54	to other in-process scripting applications such as <strong>mod_perl</strong>,
55	<strong>mod_python</strong>, and <strong>mod_ruby</strong>, and to
56	applications implemented in C as apache modules where privilege
57	separation is an issue.</p>
58
59	</summary>
60
61	<section id="security"><title>Security Considerations</title>
62
63	<p><module>mod_privileges</module> introduces new security concerns
64	in situations where <strong>untrusted code</strong> may be run
65	<strong>within the webserver process</strong>. This applies to
66	untrusted modules, and scripts running under modules such as
67	mod_php or mod_perl. Scripts running externally (e.g. as CGI
68	or in an appserver behind mod_proxy or mod_jk) are NOT affected.</p>
69
70	<p>The basic security concerns with mod_privileges are:</p>
71	<ul><li>Running as a system user introduces the same security issues
72	as mod_suexec, and near-equivalents such as cgiwrap and suphp.</li>
73	<li>A privileges-aware malicious user extension (module or script)
74	could escalate its privileges to anything available to the
75	httpd process in any virtual host. This introduces new risks
76	if (and only if) mod_privileges is compiled with the
77	<var>BIG_SECURITY_HOLE</var> option.</li>
78	<li>A privileges-aware malicious user extension (module or script)
79	could escalate privileges to set its user ID to another system
80	user (and/or group).</li>
81	</ul>
82
83	<p>The <directive>PrivilegesMode</directive> directive allows you to
84	select either <var>FAST</var> or <var>SECURE</var> mode. You can
85	mix modes, using <var>FAST</var> mode for trusted users and
86	fully-audited code paths, while imposing SECURE mode where an
87	untrusted user has scope to introduce code.</p>
88	<p>Before describing the modes, we should also introduce the target
89	use cases: Benign vs Hostile. In a benign situation, you want to
90	separate users for their convenience, and protect them and the server
91	against the risks posed by honest mistakes, but you trust your users
92	are not deliberately subverting system security. In a hostile
93	situation - e.g. commercial hosting - you may have users deliberately
94	attacking the system or each other.</p>
95	<dl>
96	<dt>FAST mode</dt>
97	<dd>In <var>FAST</var> mode, requests are run in-process with the
98	selected uid/gid and privileges, so the overhead is negligible.
99	This is suitable for benign situations, but is not secure against an
100	attacker escalating privileges with an in-process module or script.</dd>
101	<dt>SECURE mode</dt>
102	<dd>A request in <var>SECURE</var> mode forks a subprocess, which
103	then drops privileges. This is a very similar case to running CGI
104	with suexec, but for the entire request cycle, and with the benefit
105	of fine-grained control of privileges.</dd>
106	</dl>
107	<p>You can select different <directive>PrivilegesMode</directive>s for
108	each virtual host, and even in a directory context within a virtual
109	host. <var>FAST</var> mode is appropriate where the user(s) are
110	trusted and/or have no privilege to load in-process code.
111	<var>SECURE</var> mode is appropriate to cases where untrusted code
112	might be run in-process. However, even in <var>SECURE</var> mode,
113	there is no protection against a malicious user who is able to
114	introduce privileges-aware code running <em>before the start of the
115	request-processing cycle.</em></p>
116
117	</section>
118	<directivesynopsis>
119	<name>PrivilegesMode</name>
120	<description>Trade off processing speed and efficiency vs security against
121	malicious privileges-aware code.</description>
122	<syntax>PrivilegesMode FAST\|SECURE\|SELECTIVE</syntax>
123	<contextlist>
124	<context>server config</context>
125	<context>virtual host</context>
126	<context>directory</context>
127	</contextlist>
128	<compatibility>Available on Solaris 10 and OpenSolaris with
129	non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>
130	<usage><p>This directive trades off performance vs security against
131	malicious, privileges-aware code. In <var>SECURE</var> mode, each request
132	runs in a secure subprocess, incurring a substantial performance penalty.
133	In <var>FAST</var> mode, the server is not protected against escalation
134	of privileges as discussed above.</p>
135	<p>This directive differs slightly between a <code><Directory></code>
136	context (including equivalents such as Location/Files/If) and a
137	top-level or <code><VirtualHost></code>.</p>
138	<p>At top-level, it sets a default that will be inherited by virtualhosts.
139	In a virtual host, FAST or SECURE mode acts on the entire
140	HTTP request, and any settings in a <code><Directory></code>
141	context will be <strong>ignored</strong>. A third pseudo-mode
142	SELECTIVE defers the choice of FAST vs SECURE to directives in a
143	<code><Directory></code> context.</p>
144	<p>In a <code><Directory></code> context, it is applicable only
145	where SELECTIVE mode was set for the VirtualHost. Only
146	FAST or SECURE can be set in this context (SELECTIVE would be
147	meaningless).</p>
148	<note type="warning"><title>Warning</title>
149	Where SELECTIVE mode is selected for a virtual host, the activation
150	of privileges must be deferred until <em>after</em> the mapping
151	phase of request processing has determined what
152	<code><Directory></code> context applies to the request.
153	This might give an attacker opportunities to introduce
154	code through a <directive module="mod_rewrite">RewriteMap</directive>
155	running at top-level or <code><VirtualHost></code> context
156	<em>before</em> privileges have been dropped and userid/gid set.
157	</note>
158	</usage>
159	</directivesynopsis>
160
161	<directivesynopsis>
162	<name>VHostUser</name>
163	<description>Sets the User ID under which a virtual host runs.</description>
164	<syntax>VHostUser <var>unix-userid</var></syntax>
165	<default>Inherits the userid specified in
166	<directive module="mod_unixd">User</directive></default>
167	<contextlist><context>virtual host</context></contextlist>
168	<compatibility>Available on Solaris 10 and OpenSolaris with
169	non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>
170
171	<usage>
172	<p>The <directive>VHostUser</directive> directive sets the Unix userid
173	under which the server will process requests to a virtualhost.
174	The userid is set before the request is processed and reset afterwards
175	using <a
176	href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
177	>Solaris Privileges</a>. Since the setting applies to the
178	<em>process</em>, this is not compatible with threaded MPMs.</p>
179	<p><var>Unix-userid</var> is one of:</p>
180	<dl>
181	<dt>A username</dt>
182	<dd>Refers to the given user by name.</dd>
183
184	<dt><code>#</code> followed by a user number.</dt>
185	<dd>Refers to a user by its number.</dd>
186	</dl>
187
188	<note type="warning"><title>Security</title>
189	<p>This directive cannot be used to run apache as root!
190	Nevertheless, it opens potential security issues similar to
191	those discussed in the <a href="../suexec.html">suexec</a>
192	documentation.</p></note>
193	</usage>
194	<seealso><directive module="mod_unixd">User</directive></seealso>
195	<seealso><directive module="mod_suexec">SuexecUserGroup</directive></seealso>
196	</directivesynopsis>
197
198	<directivesynopsis>
199	<name>VHostGroup</name>
200	<description>Sets the Group ID under which a virtual host runs.</description>
201	<syntax>VHostGroup <var>unix-groupid</var></syntax>
202	<default>Inherits the group id specified in
203	<directive module="mod_unixd">Group</directive></default>
204	<contextlist><context>virtual host</context></contextlist>
205	<compatibility>Available on Solaris 10 and OpenSolaris with
206	non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>
207
208	<usage>
209	<p>The <directive>VHostGroup</directive> directive sets the Unix group
210	under which the server will process requests to a virtualhost.
211	The group is set before the request is processed and reset afterwards
212	using <a
213	href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
214	>Solaris Privileges</a>. Since the setting applies to the
215	<em>process</em>, this is not compatible with threaded MPMs.</p>
216	<p><var>Unix-group</var> is one of:</p>
217	<dl>
218	<dt>A group name</dt>
219	<dd>Refers to the given group by name.</dd>
220
221	<dt><code>#</code> followed by a group number.</dt>
222	<dd>Refers to a group by its number.</dd>
223	</dl>
224
225	<note type="warning"><title>Security</title>
226	<p>This directive cannot be used to run apache as root!
227	Nevertheless, it opens potential security issues similar to
228	those discussed in the <a href="../suexec.html">suexec</a>
229	documentation.</p></note>
230	</usage>
231	<seealso><directive module="mod_unixd">Group</directive></seealso>
232	<seealso><directive module="mod_suexec">SuexecUserGroup</directive></seealso>
233	</directivesynopsis>
234
235	<directivesynopsis>
236	<name>VHostSecure</name>
237	<description>Determines whether the server runs with enhanced security
238	for the virtualhost.</description>
239	<syntax>VHostSecure On\|Off</syntax>
240	<default>VHostSecure On</default>
241	<contextlist><context>virtual host</context></contextlist>
242	<compatibility>Available on Solaris 10 and OpenSolaris with
243	non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>
244
245	<usage>
246	<p>Determines whether the virtual host processes requests with
247	security enhanced by removal of <a
248	href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
249	>Privileges</a> that are rarely needed in a webserver, but which are
250	available by default to a normal Unix user and may therefore
251	be required by modules and applications. It is recommended that
252	you retain the default (On) unless it prevents an application running.
253	Since the setting applies to the <em>process</em>, this is not
254	compatible with threaded MPMs.</p>
255	<note><title>Note</title>
256	<p>If <directive>VHostSecure</directive> prevents an application
257	running, this may be a warning sign that the application should be
258	reviewed for security.</p></note>
259	</usage>
260	</directivesynopsis>
261
262	<directivesynopsis>
263	<name>VHostCGIMode</name>
264	<description>Determines whether the virtualhost can run
265	subprocesses, and the privileges available to subprocesses.</description>
266	<syntax>VHostCGIMode On\|Off\|Secure</syntax>
267	<default>VHostCGIMode On</default>
268	<contextlist><context>virtual host</context></contextlist>
269	<compatibility>Available on Solaris 10 and OpenSolaris with
270	non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>
271
272	<usage>
273	<p>Determines whether the virtual host is allowed to run fork and exec,
274	the <a
275	href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
276	>privileges</a> required to run subprocesses. If this is set to
277	<var>Off</var> the virtualhost is denied the privileges and will not
278	be able to run traditional CGI programs or scripts under the traditional
279	<module>mod_cgi</module>, nor similar external programs such as those
280	created by <module>mod_ext_filter</module> or
281	<directive module="mod_rewrite">RewriteMap</directive> <var>prog</var>.
282	Note that it does not prevent CGI programs running under alternative
283	process and security models such as <a href="http://fastcgi.coremail.cn"
284	>mod_fcgid</a>, which is a recommended solution in Solaris.</p>
285	<p>If set to <var>On</var> or <var>Secure</var>, the virtual host
286	is permitted to run external programs and scripts as above.
287	Setting <directive>VHostCGIMode</directive> <var>Secure</var> has
288	the effect of denying privileges to the subprocesses, as described
289	for <directive>VHostSecure</directive>.</p>
290	</usage>
291	</directivesynopsis>
292
293	<directivesynopsis>
294	<name>DTracePrivileges</name>
295	<description>Determines whether the privileges required by dtrace are enabled.</description>
296	<syntax>DTracePrivileges On\|Off</syntax>
297	<default>DTracePrivileges Off</default>
298	<contextlist><context>server config</context></contextlist>
299	<compatibility>Available on Solaris 10 and OpenSolaris with
300	non-threaded MPMs (<module>prefork</module> or custom MPM).</compatibility>
301
302	<usage>
303	<p>This server-wide directive determines whether Apache will run with
304	the <a
305	href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
306	>privileges</a> required to run
307	<a href="http://www.sun.com/bigadmin/content/dtrace/">dtrace</a>.
308	Note that <var>DTracePrivileges On</var> will not in itself
309	activate DTrace, but <var>DTracePrivileges Off</var> will prevent
310	it working.</p>
311	</usage>
312	</directivesynopsis>
313
314	<directivesynopsis>
315	<name>VHostPrivs</name>
316	<description>Assign arbitrary privileges to a virtual host.</description>
317	<syntax>VHostPrivs [+-]?<var>privilege-name</var> [[+-]?privilege-name] ...</syntax>
318	<default>None</default>
319	<contextlist><context>virtual host</context></contextlist>
320	<compatibility>Available on Solaris 10 and OpenSolaris with
321	non-threaded MPMs (<module>prefork</module> or custom MPM)
322	and when <module>mod_privileges</module> is compiled with the
323	<var>BIG_SECURITY_HOLE</var> compile-time option.</compatibility>
324
325	<usage>
326	<p><directive>VHostPrivs</directive> can be used to assign arbitrary <a
327	href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
328	>privileges</a> to a virtual host. Each <var>privilege-name</var>
329	is the name of a Solaris privilege, such as <var>file_setid</var>
330	or <var>sys_nfs</var>.</p>
331
332	<p>A <var>privilege-name</var> may optionally be prefixed by
333	+ or -, which will respectively allow or deny a privilege.
334	If used with neither + nor -, all privileges otherwise assigned
335	to the virtualhost will be denied. You can use this to override
336	any of the default sets and construct your own privilege set.</p>
337
338	<note type="warning"><title>Security</title>
339	<p>This directive can open huge security holes in apache, up to
340	and including running requests with root-level powers. Do not
341	use it unless you fully understand what you are doing!</p></note>
342	</usage>
343	</directivesynopsis>
344
345	<directivesynopsis>
346	<name>VHostCGIPrivs</name>
347	<description>Assign arbitrary privileges to subprocesses created
348	by a virtual host.</description>
349	<syntax>VHostPrivs [+-]?<var>privilege-name</var> [[+-]?privilege-name] ...</syntax>
350	<default>None</default>
351	<contextlist><context>virtual host</context></contextlist>
352	<compatibility>Available on Solaris 10 and OpenSolaris with
353	non-threaded MPMs (<module>prefork</module> or custom MPM)
354	and when <module>mod_privileges</module> is compiled with the
355	<var>BIG_SECURITY_HOLE</var> compile-time option.</compatibility>
356
357	<usage>
358	<p><directive>VHostCGIPrivs</directive> can be used to assign arbitrary <a
359	href="http://www.sun.com/bigadmin/features/articles/least_privilege.jsp"
360	>privileges</a> to subprocesses created by a virtual host, as discussed
361	under <directive>VHostCGIMode</directive>. Each <var>privilege-name</var>
362	is the name of a Solaris privilege, such as <var>file_setid</var>
363	or <var>sys_nfs</var>.</p>
364
365	<p>A <var>privilege-name</var> may optionally be prefixed by
366	+ or -, which will respectively allow or deny a privilege.
367	If used with neither + nor -, all privileges otherwise assigned
368	to the virtualhost will be denied. You can use this to override
369	any of the default sets and construct your own privilege set.</p>
370
371	<note type="warning"><title>Security</title>
372	<p>This directive can open huge security holes in apache subprocesses,
373	up to and including running them with root-level powers. Do not
374	use it unless you fully understand what you are doing!</p></note>
375	</usage>
376	</directivesynopsis>
377
378
379
380	</modulesynopsis>