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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><title>dropping privileges in rsyslog</title>
</head>
<body>
<h1>Dropping privileges in rsyslog</h1>
<p><b>Available since: </b> 4.1.1</p>
<p><b>Description</b>:</p>
<p>
Rsyslogd provides the ability to drop privileges by
impersonating as another user and/or group after startup.
<p>Please note that due to POSIX standards, rsyslogd always needs to start
up as root if there is a listener who must bind to a network port below 1024.
For example, the UDP listener usually needs to listen to 514 and as such
rsyslogd needs to start up as root.
<p>If you do not need this functionality, you can start rsyslog directly as an ordinary
user. That is probably the safest way of operations. However, if a startup as
root is required, you can use the $PrivDropToGroup and $PrivDropToUser config
directives to specify a group and/or user that rsyslogd should drop to after initialization.
Once this happens, the daemon runs without high privileges (depending, of
course, on the permissions of the user account you specified).
<p>There is some additional information available in the
<a href="http://wiki.rsyslog.com/index.php/Security#Dropping_Privileges">rsyslog wiki</a>.
<p><b>Configuration Directives</b>:</p>
<ul>
<li><b>$PrivDropToUser</b><br>
Name of the user rsyslog should run under after startup. Please note that
this user is looked up in the system tables. If the lookup fails, privileges are
NOT dropped. Thus it is advisable to use the less convenient $PrivDropToUserID directive.
If the user id can be looked up, but can not be set, rsyslog aborts.
<br>
</li>
<li><b>$PrivDropToUserID</b><br>
Much the same as $PrivDropToUser, except that a numerical user id instead of a name
is specified.Thus, privilege drop will always happen.
rsyslogd aborts.
<li><b>$PrivDropToGroup</b><br>
Name of the group rsyslog should run under after startup. Please note that
this user is looked up in the system tables. If the lookup fails, privileges are
NOT dropped. Thus it is advisable to use the less convenient $PrivDropToGroupID directive.
Note that all supplementary groups are removed from the process if $PrivDropToGroup is
specified.
If the group id can be looked up, but can not be set, rsyslog aborts.
<br>
</li>
<li><b>$PrivDropToGroupID</b><br>
Much the same as $PrivDropToGroup, except that a numerical group id instead of a name
is specified. Thus, privilege drop will always happen.
</ul>
<p>[<a href="rsyslog_conf.html">rsyslog.conf overview</a>]
[<a href="manual.html">manual index</a>] [<a href="http://www.rsyslog.com/">rsyslog site</a>]</p>
<p><font size="2">This documentation is part of the <a href="http://www.rsyslog.com/">rsyslog</a>
project.<br>
Copyright © 2008 by <a href="http://www.gerhards.net/rainer">Rainer
Gerhards</a> and
<a href="http://www.adiscon.com/">Adiscon</a>.
Released under the GNU GPL version 3 or higher.</font></p>
</body></html>
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