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mirror of https://github.com/nmap/nmap.git synced 2026-01-07 23:19:02 +00:00

revert 8824 to give us a bit more time to think about what to do about service name capitalization

This commit is contained in:
fyodor
2008-07-13 09:11:22 +00:00
parent 9555299a28
commit 3206168fb8
2 changed files with 38 additions and 38 deletions

View File

@@ -222,7 +222,7 @@ you would expect.</para>
<para>Reads target specifications from
<replaceable>inputfilename</replaceable>. Passing a huge
list of hosts is often awkward on the command line, yet it
is a common desire. For example, your dhcp server might
is a common desire. For example, your DHCP server might
export a list of 10,000 current leases that you wish to
scan. Or maybe you want to scan all IP addresses
<emphasis>except</emphasis> for those to locate hosts using
@@ -1049,11 +1049,11 @@ one of the TCP scan types. As a memory aid, port scan type options
are of the form <option>-s<replaceable>C</replaceable></option>, where
<replaceable>C</replaceable> is a prominent character in the scan
name, usually the first. The one exception to this is the deprecated
ftp bounce scan (<option>-b</option>). By default, Nmap performs a
FTP bounce scan (<option>-b</option>). By default, Nmap performs a
SYN Scan, though it substitutes a connect scan if the user does not
have proper privileges to send raw packets (requires root access on
Unix) or if IPv6 targets were specified. Of the scans listed in this
section, unprivileged users can only execute connect and ftp bounce
section, unprivileged users can only execute connect and FTP bounce
scans.</para>
<variablelist>
@@ -1137,7 +1137,7 @@ know that she has been connect scanned.</para>
<para>While most popular services on the Internet run over the TCP
protocol, <ulink
role="hidepdf" url="http://www.rfc-editor.org/rfc/rfc768.txt">UDP</ulink> services
are widely deployed. DNS, snmp, and dhcp
are widely deployed. DNS, SNMP, and DHCP
(registered ports 53, 161/162, and 67/68) are three of the most
common. Because UDP scanning is generally slower and more difficult
than TCP, some security auditors ignore these ports. This is a mistake, as
@@ -1478,46 +1478,46 @@ after retransmissions, the protocol is marked
<varlistentry>
<term>
<option>-b <replaceable>ftp relay host</replaceable></option> (ftp bounce scan)
<option>-b <replaceable>FTP relay host</replaceable></option> (FTP bounce scan)
<indexterm><primary><option>-b</option></primary></indexterm>
<indexterm><primary>ftp bounce scan</primary></indexterm>
<indexterm><primary>FTP bounce scan</primary></indexterm>
</term>
<listitem>
<para>An interesting feature of the ftp protocol (<ulink
<para>An interesting feature of the FTP protocol (<ulink
role="hidepdf" url="http://www.rfc-editor.org/rfc/rfc959.txt">RFC 959</ulink>) is
support for so-called proxy ftp connections. This allows a user to
connect to one ftp server, then ask that files be sent to a
support for so-called proxy FTP connections. This allows a user to
connect to one FTP server, then ask that files be sent to a
third-party server. Such a feature is ripe for abuse on many levels,
so most servers have ceased supporting it. One of the abuses this
feature allows is causing the ftp server to port scan other hosts.
Simply ask the ftp server to send a file to each interesting port of a
feature allows is causing the FTP server to port scan other hosts.
Simply ask the FTP server to send a file to each interesting port of a
target host in turn. The error message will describe whether the port
is open or not. This is a good way to bypass firewalls because
organizational ftp servers are often placed where they have
more access to other internal hosts than any old Internet host would. Nmap supports ftp
organizational FTP servers are often placed where they have
more access to other internal hosts than any old Internet host would. Nmap supports FTP
bounce scan with the <option>-b</option> option. It takes an argument
of the form
<replaceable>username</replaceable>:<replaceable>password</replaceable>@<replaceable>server</replaceable>:<replaceable>port</replaceable>.
<replaceable>Server</replaceable> is the name or IP address of a
vulnerable ftp server. As with a normal URL, you may omit
vulnerable FTP server. As with a normal URL, you may omit
<replaceable>username</replaceable>:<replaceable>password</replaceable>,
in which case anonymous login credentials (user:
<literal>anonymous</literal> password:<literal>-wwwuser@</literal>)
are used. The port number (and preceding colon) may be omitted as
well, in which case the default ftp port (21) on
well, in which case the default FTP port (21) on
<replaceable>server</replaceable> is used.</para>
<para>This vulnerability was widespread in 1997 when Nmap was
released, but has largely been fixed. Vulnerable servers are still
around, so it is worth trying when all else fails. If bypassing a
firewall is your goal, scan the target network for open port 21 (or
even for any ftp services if you scan all ports with version
even for any FTP services if you scan all ports with version
detection), then try a bounce scan using each. Nmap will tell you
whether the host is vulnerable or not. If you are just trying to
cover your tracks, you don't need to (and, in fact, shouldn't) limit
yourself to hosts on the target network. Before you go scanning
random Internet addresses for vulnerable ftp servers, consider that
random Internet addresses for vulnerable FTP servers, consider that
sysadmins may not appreciate you abusing their servers in this
way.</para>
@@ -1575,7 +1575,7 @@ way.</para>
Ports can also be specified by name according to what the
port is referred to in the <filename>nmap-services</filename>. You
can even use the wildcards * and ? with the names. For example, to scan
ftp and all ports whose names begin with http, use <option>-p ftp,http*</option>.
FTP and all ports whose names begin with http, use <option>-p ftp,http*</option>.
Be careful about shell expansions and quote the argument to <option>-p</option> if unsure.</para>
<para>Ranges of ports can be surrounded by square brackets to indicate
@@ -1639,7 +1639,7 @@ way.</para>
database of about 2,200
well-known services,<indexterm><primary>well-known ports</primary></indexterm>
Nmap would report that those ports probably correspond to a
mail server (smtp), web server (http), and name server (DNS)
mail server (SMTP), web server (HTTP), and name server (DNS)
respectively. This lookup is usually accurate&mdash;the vast
majority of daemons listening on TCP port 25 are, in fact, mail
servers. However, you should not bet your security on this!
@@ -1648,7 +1648,7 @@ way.</para>
</para>
<para>Even if Nmap is right, and the hypothetical server above is
running smtp, http, and DNS servers, that is not a lot of
running SMTP, HTTP, and DNS servers, that is not a lot of
information. When doing vulnerability assessments (or even simple
network inventories) of your companies or clients, you really want
to know which mail and DNS servers and versions are
@@ -1664,11 +1664,11 @@ way.</para>
database contains probes
for querying various services and match expressions to recognize
and parse responses. Nmap tries to determine the service protocol
(e.g. ftp, ssh, telnet, http), the application name (e.g. ISC
(e.g. FTP, SSH, telnet, HTTP), the application name (e.g. ISC
BIND, Apache httpd, Solaris telnetd), the version number,
hostname, device type (e.g. printer, router), the OS family
(e.g. Windows, Linux) and sometimes miscellaneous details like
whether an X server is open to connections, the ssh protocol
whether an X server is open to connections, the SSH protocol
version, or the KaZaA user name). Of course, most services don't
provide all of this information. If Nmap was compiled with
OpenSSL support, it will connect to SSL servers to deduce the
@@ -1701,7 +1701,7 @@ way.</para>
on the port. Please take a couple minutes to make the submission
so that your find can benefit everyone. Thanks to these
submissions, Nmap has about 3,000 pattern matches for more than
350 protocols such as smtp, ftp, http, etc.<indexterm><primary>submission of service fingerprints</primary></indexterm>
350 protocols such as SMTP, FTP, HTTP, etc.<indexterm><primary>submission of service fingerprints</primary></indexterm>
</para>
<para>Version detection is enabled and controlled with the
@@ -2611,7 +2611,7 @@ It even supports mechanisms for bypassing poorly implemented
defenses. One of the best methods of understanding your
network security posture is to try to defeat it. Place yourself in
the mind-set of an attacker, and deploy techniques from this section
against your networks. Launch an ftp bounce scan, idle scan,
against your networks. Launch an FTP bounce scan, idle scan,
fragmentation attack, or try to tunnel through one of your own
proxies.</para>
@@ -2638,9 +2638,9 @@ used by administrators to enhance security. The problem with this
logic is that these methods would still be used by attackers, who
would just find other tools or patch the functionality into Nmap.
Meanwhile, administrators would find it that much harder to do their
jobs. Deploying only modern, patched ftp servers is a far more
jobs. Deploying only modern, patched FTP servers is a far more
powerful defense than trying to prevent the distribution of tools
implementing the ftp bounce attack.
implementing the FTP bounce attack.
</para>
<para>There is no magic bullet (or Nmap option) for detecting and
@@ -2813,14 +2813,14 @@ this comes about. An administrator will set up a shiny new firewall,
only to be flooded with complains from ungrateful users whose
applications stopped working. In particular, DNS may be broken
because the UDP DNS replies from external servers can no longer enter
the network. ftp is another common example. In active ftp transfers,
the network. FTP is another common example. In active FTP transfers,
the remote server tries to establish a connection back to the client
to transfer the requested file.</para>
<para>Secure solutions to these problems exist, often in the form of
application-level proxies or protocol-parsing firewall modules.
Unfortunately there are also easier, insecure solutions. Noting that
DNS replies come from port 53 and active ftp from port 20, many administrators
DNS replies come from port 53 and active FTP from port 20, many administrators
have fallen into the trap of simply allowing incoming traffic from
those ports. They often assume that no attacker would notice and
exploit such firewall holes. In other cases, administrators consider this a
@@ -2832,10 +2832,10 @@ solution. Then they forget the security upgrade.
into this trap. Numerous products have shipped with these insecure
rules. Even Microsoft has been guilty. The IPsec filters that
shipped with Windows 2000 and Windows XP contain an implicit rule that
allows all TCP or UDP traffic from port 88 (kerberos). In another well-known
allows all TCP or UDP traffic from port 88 (Kerberos). In another well-known
case, versions of the Zone Alarm personal firewall up to 2.1.25
allowed any incoming UDP packets with the source port 53 (DNS) or 67
(dhcp).</para>
(DHCP).</para>
<para>Nmap offers the <option>-g</option> and
<option>--source-port</option> options (they are equivalent) to exploit these
@@ -3207,7 +3207,7 @@ output for lack of a place to put them.</para>
simple format that lists each host on one line and can be trivially
searched and parsed with standard Unix tools such as grep, awk, cut,
sed, diff, and Perl. Even I usually use it for one-off tests done at the
command line. Finding all the hosts with the ssh port open or that
command line. Finding all the hosts with the SSH port open or that
are running Solaris takes only a simple grep to identify the hosts,
piped to an awk or cut command to print the desired fields.</para>
@@ -3932,8 +3932,8 @@ overwhelming requests. Specify <option>--open</option> to only see
<para>Launches host enumeration and a TCP scan at the first half
of each of the 255 possible 8 bit subnets in the 198.116 class B
address space. This tests whether the systems run ssh, DNS, pop3,
or imap on their standard ports, or anything on port 4564. For any
address space. This tests whether the systems run SSH, DNS, POP3,
or IMAP on their standard ports, or anything on port 4564. For any
of these ports found open, version detection is used to determine
what application is running.</para>

View File

@@ -22,8 +22,8 @@
<para>This is Nmap's bread and butter. Examples include
looking up whois data based on the target domain,
querying ARIN, RIPE, or APNIC for the target IP to determine ownership,
performing identd lookups on open ports, snmp queries, and
listing available nfs/smb/RPC shares and services.</para>
performing identd lookups on open ports, SNMP queries, and
listing available NFS/SMB/RPC shares and services.</para>
</listitem>
</varlistentry>
@@ -36,7 +36,7 @@
is able to recognize thousands of different services through
its probe and regular expression based matching system, but it
cannot recognize everything. For example, identifying the Skype v2 service requires two
independent probes. Nmap could also recognize more snmp services
independent probes. Nmap could also recognize more SNMP services
if it tried a few hundred different community names by brute
force. Neither of these tasks are well suited to traditional
Nmap version detection, but both are easily accomplished with
@@ -143,7 +143,7 @@ The reference manual is also
and produce results below the port table. <xref
linkend="nse-ex1"/> shows a typical script scan. Examples of
service scripts producing output are <literal>Stealth SSH
version</literal>, which tricks some ssh servers into divulging
version</literal>, which tricks some SSH servers into divulging
version information without logging the attempt as they normally
would, <literal>Service Owner</literal>, which connects to open
ports, then performs a reverse-identd query to determine what
@@ -280,7 +280,7 @@ Nmap finished: 1 IP address (1 host up) scanned in 0.907 seconds
</term>
<listitem>
<para>These scripts try to actively learn more about the
network by querying public registries, snmp-enabled
network by querying public registries, SNMP-enabled
devices, directory services, and the like.</para>
</listitem>
</varlistentry>