Nmap Copyright and Licensing
The Nmap Security Scanner is (C) 1996–2018 Insecure.Com
LLC ("The Nmap Project"). Nmap is also a registered trademark of the
Nmap Project. This program free software; you may redistribute
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; Version 2
(“GPL”), BUT ONLY WITH ALL OF THE CLARIFICATIONS AND
EXCEPTIONS DESCRIBED HEREIN. This guarantees your right to use,
modify, and redistribute this software under certain conditions. If
you wish to embed Nmap technology into proprietary software, we sell
alternative licenses (contact
of software vendors already license Nmap technology such as host
discovery, port scanning, OS detection, version detection, and the
Nmap Scripting Engine.
Note that the GPL places important restrictions on “derivative works”,
yet it does not provide a detailed definition of that term. To avoid
misunderstandings, we interpret that term as broadly as copyright law
allows. For example, we consider an application to constitute a
derivative work for the purpose of this license if it does any of the
following with any software or content covered by this license
Integrates source code from Covered Software.
Reads or includes copyrighted data files, such as
Is designed specifically to execute Covered Software and parse the results (as opposed to typical shell or execution-menu apps, which will execute anything you tell them to).
Includes Covered Software in a proprietary executable
installer. The installers produced by InstallShield are an example of
this. Including Nmap with other software in compressed or archival
form does not trigger this provision, provided appropriate open source
decompression or de-archiving software is widely available for no
charge. For the purposes of this license, an installer is considered
to include Covered Software even if it actually retrieves a copy of
Covered Software from another source during runtime (such as by
downloading it from the Internet).
Links (statically or dynamically) to a library which does any of the above.
Executes a helper program, module, or script to do any of the above.
This list is not exclusive, but is meant to clarify our interpretation
of derived works with some common examples. Other people may
interpret the plain GPL differently, so we consider this a special
exception to the GPL that we apply to Covered Software. Works which
meet any of these conditions must conform to all of the terms of this
license, particularly including the GPL Section 3 requirements of
providing source code and allowing free redistribution of the work as
As another special exception to the GPL terms, the Nmap Project grants
permission to link the code of this program with any version of the
OpenSSL library which is distributed under a license identical to that
listed in the included
file, and distribute linked combinations including the
The Nmap Project has permission to redistribute Npcap, a packet
capturing driver and library for the Microsoft Windows platform.
Npcap is a separate work with it's own license rather than this Nmap
license. Since the Npcap license does not permit redistribution
without special permission, our Nmap Windows binary packages which
contain Npcap may not be redistributed without special
Any redistribution of Covered Software, including any derived works,
must obey and carry forward all of the terms of this license, including
obeying all GPL rules and restrictions. For example, source code of
the whole work must be provided and free redistribution must be
allowed. All GPL references to "this License", are to be treated as
including the terms and conditions of this license text as well.
Because this license imposes special exceptions to the GPL, Covered
Work may not be combined (even as part of a larger work) with plain
GPL software. The terms, conditions, and exceptions of this license
must be included as well. This license is incompatible with some
other open source licenses as well. In some cases we can relicense
portions of Nmap or grant special permissions to use it in other open
source software. Please contact firstname.lastname@example.org with any such
requests. Similarly, we don't incorporate incompatible open source
software into Covered Software without special permission from the
If you have any questions about the licensing restrictions on using
Nmap in other works, we are happy to help. As mentioned above, we
also offer an alternative license to integrate Nmap into proprietary
applications and appliances. These contracts have been sold to dozens
of software vendors, and generally include a perpetual license as well
as providing support and updates. They also fund the continued
development of Nmap. Please email
<email@example.com> for further
If you have received a written license agreement or
contract for Covered Software stating terms other than these, you may
choose to use and redistribute Covered Software under those terms
instead of these.
Creative Commons License for this Nmap Guide
This Nmap Reference Guide is (C) 2005–2018 Insecure.Com LLC. It is
hereby placed under version 3.0 of the Creative Commons
Attribution License. This allows you redistribute and modify
the work as you desire, as long as you credit the original source.
Alternatively, you may choose to treat this document as falling under
the same license as Nmap itself (discussed previously).
Source Code Availability and Community Contributions
Source is provided to this software because we believe users
have a right to know exactly what a program is going to do before they
run it. This also allows you to audit the software for security holes.
Source code also allows you to port Nmap to new platforms, fix
bugs, and add new features. You are highly encouraged to send your
<firstname.lastname@example.org> for possible incorporation into
the main distribution. By sending these changes to Fyodor or one of
the Insecure.Org development mailing lists, it is assumed that you are
offering the Nmap Project the unlimited, non-exclusive right to reuse,
modify, and relicense the code. Nmap will always be available open
source, but this
is important because the inability to relicense code has caused
devastating problems for other Free Software projects (such as KDE and
NASM). We also occasionally relicense the code to third parties as
discussed above. If you wish to specify special license conditions of
your contributions, just say so when you send them.
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 v2.0 for more details at http://www.gnu.org/licenses/gpl-2.0.html, or in the
included with Nmap.
It should also be noted that Nmap has occasionally been known to crash
poorly written applications, TCP/IP stacks, and even operating
While this is extremely rare, it is important to keep in
mind. Nmap should never be run against mission
critical systems unless you are prepared to suffer
downtime. We acknowledge here that Nmap may crash your systems or
networks and we disclaim all liability for any damage or problems Nmap
Because of the slight risk of crashes and because a few black
hats like to use Nmap for reconnaissance prior to attacking systems,
there are administrators who become upset and may complain when their
system is scanned. Thus, it is often advisable to request permission
before doing even a light scan of a network.
Nmap should never be installed with special privileges
(e.g. suid root).
That would open up a major security vulnerability as other users on the
system (or attackers) could use it for privilege escalation.
Third-Party Software and Funding Notices
This product includes software developed by
the Apache Software
Foundation. A modified version of the Libpcap portable packet capture
is distributed along with Nmap.
The Windows version of Nmap utilizes the Libpcap-derived
Regular expression support is provided by the
which is open-source software, written by Philip Hazel.
Certain raw networking functions use the
networking library, which was written by Dug Song.
A modified version is distributed with Nmap.
Nmap can optionally link with the
for SSL version detection support.
The Nmap Scripting Engine uses an embedded version of
the Lua programming
language. The Liblinear
linear classification library is used for our
IPv6 OS detection machine
learning techniques (see the section called “IPv6 matching”).
All of the third-party software described in this paragraph is freely
redistributable under BSD-style software licenses.
Binary packages for Windows and Mac OS X include support libraries
necessary to run Zenmap and Ndiff with Python and PyGTK. (Unix platforms
commonly make these libraries easy to install, so they are not part of
the packages.) A listing of these support libraries and their licenses
is included in the
This software was supported in part through the Google Summer of Code and the DARPA CINDER program (DARPA-BAA-10-84).
United States Export Control
Nmap only uses encryption when compiled with the optional
OpenSSL support and linked with OpenSSL. When compiled without
OpenSSL support, the Nmap Project believes that Nmap is not subject to
Administration Regulations (EAR) export control. As such,
there is no applicable ECCN (export control classification number) and
exportation does not require any special license, permit, or other
When compiled with OpenSSL support or distributed as source
code, the Nmap Project believes that Nmap falls under
(“Information Security Software”). We distribute Nmap
under the TSU exception for publicly available encryption