Nikto(1)

NAME
Nikto - Web Server and CGI Scanner, Version 1.34

SYNOPSIS
nikto.pl [-h target] [options]

WARNING
Nikto is a tool for finding default web files and examing web server and CGI security. It makes a lot of reqeusts to the remote server, which in some cases may cause the server to crash. It may also be illegal to use this software against servers you do not have permission to do test.

DESCRIPTION
Nikto is designed to examine web servers and look for items in multiple categories:

    •   misconfigurations

    •   default files and scripts

    •   insecure files and scripts

    •   outdated software

It uses Rain Forest Puppy's LibWhisker (wiretrip.net) for HTTP functionality, and can perform checks in HTTP or HTTPS. It also supports basic port scanning and will determine if a web server is running on any open ports.

Nikto checks and code can be automatically udpated from the main distribution server by using the -update option (see below) to ensure Nikto is checking the most recent vulnerabilities.

Nikto will also load user defined checks at startup if they are placed in a file named user_scan_database.db in the plugins directory. Unlike scan_database.db, this file will not be over-written if the -update option is used. This should always be used if you add your own checks (and you should send those checks to sullo@cirt.net).

Nikto leaves a footprint on a server it scans--both in an invalid 404 check and in the User-Agent header. This can be changed by forcing the $NIKTO{fingerprint} and $NIKTO{useragent} to new values in the source code, or, if any IDS evasion (-e) option is used. Note that it's pretty obvious when Nikto is scanning a server anyway--the large number of invalid requests sticks out a lot in the server logs, although with an IDS evasion technique it might not be extremely obvious that it was Nikto.

Why the name Nikto? See the movies "The Day the Earth Stood Still" and, of course "Army of Darkness" for the answer. For a full list of pop-culture references to this, see http://www.blather.net/archives2/issue2no21.html which has a lot of good information.

OPTIONS
The options listed below are all optional except the -h target specification. They can all be abbreviated to the first letter (i.e., -m for -mutate), with the exception of -verbose and -debug.

-config <config file>
    Read the specified configuration file instead of the default one.

-Cgidirs <dirs>
    Optionally force the CGI directories to scan. Valid values are 'none' to not check any, 'all' to force scan all CGi directories (like the deprecated -allcgi), or a value to use as the CGI directory, i.e. '/cgi/'.

-cookies
    Print out the cookie names and values that were received during the scan.

-evasion <evasion method>
    IDS evasion techniques. This enables the intrusion detection evasion in LibWhisker. Multiple options can be used by stringing the numbers together, i.e. to enable methods 1 and 5, use "-e 15". The valid options are (use the number preceeding each description):

    1   Random URI encoding (non-UTF8)

    2   Add directory self-reference /./

    3   Premature URL ending

    4   Prepend long random string to request

    5   Fake parameters to files

    6   TAB as request spacer instead of spaces

    7   Random case sensitivity

    8   Use Windows directory separator \ instead of /

    9   Session splicing

    See the LibWhisker source for more information, or http://www.wiretrip.net/

-findonly
    Use port scan to find valid HTTP and HTTPS ports only, but do not perform checks against them.

-Format
    Output format for the file specified with the -output option. Valid formats are:

    HTM HTML output format.

    TXT Text output format. This is the default if -F is not specified.

    CSV Comma Seperated Value format.

-generic
    Force full scan rather than trusting the "Server:" identification string, as many servers allow this to be changed.

-host <ip, hostname or file>
    Target host(s) to check against. This can be an IP address or hostname, or a file of IPs or hostnames. If this argument is a file, it should formatted as described below. This is the only required option.

-id <user:password:realm>
    HTTP Authentication use, format is userid:password for authorizing Nikto a web server realm. For NTLM realms, format is id:password:realm.

-mutate
    Mutate checks. This causes Nikto put all files with all directories from the .db files and can the host. You might find some oddities this way. Note that it generates a lot of checks.

-nolookup
    Don't perform a host name lookup.

-output <filename>
    Write output to this file when complete. Format is text unless specified via -Format.

-port <port number>
    Port number to scan, defaults to port 80 if missing. This can also be a range or list of ports, which Nikto will check for web servers. If a web server is found, it will perform a full scan unless the -f option is used.

-root <root>
    Always prepend this to requests, i.e., changes a request of "/password.txt" to "/directory/password.txt" (assuming the value passed on the CLI was "/directory")

-ssl
    Force SSL mode on port(s) listed. Note that Nikto attempts to determine if a port is HTTP or HTTPS automatically, but this can be slow if the server fails to respond or is slow to respond to the incorrect one. This sets SSL usage for all hosts and ports.

-timeout  <timeout>
    Set timeout for each request, default is 10 seconds

-useproxy
    Use the proxy defined in config.txt for all requests

-vhost <ip or hostname>
    Virtual host to use for the "Host:" header, in case it is different from the target.

-Version
    Print version numbers of Nikto, all plugins and all databases.

These options cannot be abbreviated to the first letter:

-dbcheck
    This option will check the syntax of the checks in the scan_database.db and user_scan_database.db files. This is really only useful if you are adding checks or are having problems.

-debug
    Print a huge amount of detail out. In most cases this is going to be more information than you need, so try -verbose first.

-update
    This will connect to cirt.net and download updated scan_database.db and plugin files. Use this with caution as you are downloading files--perhaps including code--from an "untrusted" source. This option cannot be combined with any other, but required variables (like the PROXY settings) will be loaded from the config.txt file.

-verbose
    Print out a lot of extra data during a run. This can be useful if a scan or server is failing, or to see exactly how a server responds to each request.

HOSTNAME FILE
If a file is specified with -h instead of a hostname or IP, Nikto will open the file to use it as a list of targets. The file should be formatted with one host per line. If no port is specified, port 80 is assumed. Multiple ports may be specified per host. If a host file is used, any ports specified via -p are added to every host. Valid lines would be:

    10.100.100.100
    10.100.100.100:443
    10.100.100.100,443
    10.100.100.100:443:8443
    10.100.100.100,443,8443
    evilash.example.com,80
    (etc)

CONFIG FILE
The config.txt file provides a means to set variables at run-time without modifying the Nikto source itself. The options below can be set in the file. Options that accept multiple values (CGIDIRS, SKIPPORTS, etc.) should just use a space to distinguish multiple values. None of these are required unless you need them.

CLIOPTS
    Add any option here to be added to every Nikto execution, whether specified at the command line or not.

NMAP
    Path to nmap. If defined, Nikto will use nmap to port scan a host rather than PERL code, and so should be faster.

SKIPPORTS
    Port number never to scan (so you don't crash services, perhaps?).

PROXYHOST
    Server to use as a proxy, either IP or hostname, no 'http://' needed.

PROXYPORT
    Port number that PROXYHOST uses as a proxy.

PROXYUSER
    If the PROXYHOST requires authentication, use this ID. Nikto will prompt for it if this is not set & it is needed.

PROXYPASS
    If the PROXYHOST requires a password for PROXYUSER, use this password. Nikto will prompt for it if this is not set & it is needed.

PLUGINDIR
    If Nikto can't find it's plugin directory for some reason, enter the full path and the problem is solved.

UPDATES
    Turns data push to cirt.net on. Please see the CIRT.NET UPDATES section for details.

MAX_WARN
    If the number of OK or MOVED messages reaches this number, a warning will printed.

PROMPTS
    If set to "no", Nikto will never prompt for anything--proxy auth, updates, nothing...

DEFAULTHTTPVER
    First try this HTTP method. If this fails, Nikto will attempt to find a valid one. Useful if you want try something non-standard.

STATIC-COOKIE
    The name/value of this cookie, if set, will be sent for every request (useful for auth cookies).

Variables that start with the 'at' sign (@) will be used when scan rules are loaded. For each value (seperated by space), the rule will be duplicated. See the TEST DATABASES section for more information.

Predefined variables are:

@CGIDIRS
    CGI directories to look for, valid ones (or all) will be used for CGI checks against the remote host.

@MUTATEDIRS
    Additional directories to use when operating under the Mutate mode besides ones already defined the .db files.

@MUTATEFILES
    Additional files to use when operating under the Mutate mode besides ones already defined the .db files.

@ADMINDIRS
    Typical administration directories.

@USERS
    Typical user names for the user guessing plugins.

CIRT.NET UPDATES
In order to help keep the Nikto databases up-to-date, you have the ability to easily submit some updates back to cirt.net for inclusion in new copies of the databases. Currently, this only includes software versions (such as "Apache/7.0.3"). If Nikto scans a host and sees a newer version on the host than it has in the database, or it is missing entirely, (and your databases are fairly recent), this information can be automatically (or manually) sent back to cirt.net.

Behaviour of this option is controlled in config.txt through the UPDATES variable. If UPDATES is set to "no", Nikto will not send or ask about sending values to cirt.net. If set to "auto", it will automatically send the data through an HTTP request. If set to "yes" (which is the default), when there are updates it will ask if you would like to submit and show you the data (unless PROMPTS=no).

There is only one thing submitted to cirt.net when you do this: the "updated" version string. No information specific to the host tested is sent. No information from the scanning source is sent (it does log your IP address as seen by cirt.net's web server, but... nothing else).

If you're not comfortable with this, you may also email it to me at sullo@cirt.net or just set UPDATES=no. Please don't complain and say I'm stealing your data... just trying to save me some work ;)

Again: the default configuration of Nikto does not send any data to cirt.net.

TEST DATABASES
Rules in the scan databases can use dynamic variables from config.txt. Any variable that starts with the 'at' sign (@) will be substited in rules. For example: A rule of

    "generic","@CGIDIRStest.html","200","GET","Test"

with "@CGIDIRS=/cgi-bin/ /cgi-sys/" will test for:

    •   /cgi-bin/test.html

    •   /cgi-sys/test.html

Any number of these variables can be set, and any number can be used in a rule (i.e., "@CGIDIRS@ADMINDIRStest.html"). Additionally, the generic @HOSTNAME and @IP are available, which use the current target's hostname or IP.

Rules can be specified which also have conditionals for test success. This can allow a test to look for a 200 HTTP response but not contain the word "home". This would look like "200!home" in the scan_database.db file.

EXAMPLES
A basic scan of a web server on port 80. The -h option is the only option that is required for a basic scan of a web server on the standard HTTP port.

    nikto.pl -h 10.100.100.10

A basic scan of a web server on port 443, forcing SSL encryption and ignoring the Server header. Note that Nikto does not assume port 443 to be SSL, but if HTTP fails it will try HTTPS.

    nikto.pl -h 10.100.100.10 -p 443 -s -g

Scanning multiple ports on the server, letting Nikto determine if they are HTTP and SSL encrypted.

    nikto.pl -h 10.100.100.10 -p 80-90

Scanning specific ports on the system.

    nikto.pl -h 10.100.100.10 -p 80,443,8000,8080

You may combine IDS evasion techniques as desired.

    nikto.pl -h 10.100.100.10 -p 80 -e 167

IMPORTANT FILES

config.txt
    run-time configuration options, see the CONFIG FILE section

nikto_core.plugin
    main Nikto code, absolutely required

nikto_plugin_order.txt
    determines the order in which plugins are executed

LW.pm
    The stand-alone LibWhisker file.

user_scan_database.db
    If it exists in the plugins directory, it will load these checks as well. Same syntax as scan_database.db

ADDITIONAL SOFTWARE
LibWhisker is required for proper execution of Nikto. The LW.pm library is included with Nikto, but it is recommended that you download and install the full LibWhisker module from http://www.wiretrip.net/. If you are not using an installed Libwhisker, you will need to change Nikto.pl so that it includes the proper LW.pm file. Edit Nikto.pl and comment the line:

    require "$NIKTO{plugindir}/LW.pm";

and uncomment the line below it:

    use LW;

nmap can be used to speed up port scans. This should be much faster than relying on PERL code to perform port scans. Nmap can be obtained from http://www.nmap.org/, it is not included with Nikto.

SSL software is required to test using HTTPS. For Windows systems, the SSL software and libraries can be obtained from http://www.activestate.com/. For unix systems, OpenSSL from http://www.openssl.org/ and the Net::SSLeay module from http://www.cpan.org/ are required.

CHECKS
Checks, both information and actual security problems, are derived from a number of sources. These include the mailing lists BugTraq, NTBugTraq, WebAppSec (WWW-Mobile-Code), and others. The web sites www.securitytracker.com, www.securiteam.com, www.packetstormsecurity.com and www.securityfocus.com. Additionally, updates to Nessus are watched and many thanks to all the plugin writers (and to Renaud for Nessus itself) (http://www.nessus.org/).

WARNINGS
Nikto can cause harm to your local system, the remote system and/or the network. Some options can generate over 70,000 HTTP requests to a target. Do not run Nikto againsts hosts you are not authorized to perform testing against. Cirt.net takes no responsibility for anything done with this software, any problems it may cause or problems it may find.

Plugins are standard PERL. They are included and executed when Nikto is run. If you run the -update option, new and updated plugins will be downloaded from cirt.net. This means you are downloading code, and potentially running it, without viewing it yourself. Please consider the implications. Do not assume code distributed from Cirt.net is not harmful, as accidents happen and a malicious third party may have inserted a dangerous plugin. Cirt.net assumes no responsibility if any malicious code is delivered via the -update option.

DISTRIBUTION
Nikto and updated databases and plugins is distributed from http://www.cirt.net/

SEE ALSO

LibWhisker
    http://www.wiretrip.net/

Nmap
    http://www.nmap.org/

OpenSSL
    http://www.openssl.org/

CPAN
    http://www.cpan.org/

ActiveState
    http://www.activestate.com/

Nessus
    http://www.nessus.org/

LICENSE
This copyright applies to all code included in this distribution, but does not include the LibWhisker software, which is distributed under its own license.

Copyright (C) 2001-2005 Sullo/CIRT.net

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

Contact Information: See the AUTHOR section.

AUTHOR
Sullo, sullo@cirt.net
http://www.cirt.net/

Suggestions/fixes/support from: Jericho/attrition.org, rfp/wiretrip.net, Zel/firewallmonkeys.com, Zeno/cgisecurity.com, Darby/cirt.net, Valdez/cirt.net, S Saady, P Eronen/nixu.com, M Arboi, T Seyrat, J DePriest, P Woroshow, fr0stman, E Udassin, H Heimann and more

Many tests and contributed/suggested by: M Richardson, Jericho/attrition.org, Prickley Paw, M Arboi, H Heimann and more

And Xiola.net for kicking ass.