Download Nmap 5.21

Nmap is a program for exploring and monitoring a network. It is designed to scan a large network without delays, and also runs smoothly on a single host. The program uses so-called ‘raw ip packets’ to retrieve active hosts and information about the available services. More information about the possibilities can be found at this page. The developers have now released version 5.21, which fixes some bugs from the previous release. The corresponding announcement looks like this:

Nmap 5.21 released

Hello everyone. I’m pleased to release Nmap 5.21, which contains zero exciting new features! It is a bug-fix only release instead, addressing about a dozen issues discovered since 5.20. Thanks for all the testing and bug reports! None of the bugs are critical, but we wanted to polish things up since 5.21 may be the latest stable version for a while. That gives us time to tackle and stabilize big development projects. If you want to know what we’re up to, join the nmap-dev list.

The Nmap 5.21 source code and packages for Linux, Mac, and Windows are available for download at the usual place.

If you find any bugs, let us know on nmap-dev (http://nmap.org/book/man-bugs.html). If you find a big enough problem, you could inspire a 5.22 release.

Here are the CHANGELOG entries since 5.20:

• [Zenmap] Added a workaround for a Ubuntu 9.10 Python packaging idiosyncrasy. As of version python2.6-2.6.4-0ubuntu3, Ubuntu’s distutils modifies self.prefix, a variable we use in the setup.py script. This would cause Zenmap to look in the wrong place for its configuration files, and show the dialog “Error creating the per-user configuration directory” with the specific error “[Errno 2] No such file or directory: ‘/usr/share/zenmap/config'”. This problem was reported by Chris Clements, who also helped debug. [David]
• Fixed an error that occurred when UDP scan was combined with version scan. UDP ports would appear in the state “unknown” at the end of the scan, and in some cases an assertion failure would be raised. This was an unintended side effect of the memory use reduction changes in 5.20. The bug was reported by Jon Kibler. [David]
• [NSE] Did some simple bit-flipping on the nmap_service.exe program used by the smb-psexec script, to avoid its being falsely detected as malware by dumb antivirus signatures. [Ron]
• [NSE] Fixed a bug in http.lua that could lead to an assertion failure. It happened when there was an error getting the a response at the beginning of a batch in http.pipeline. The symptoms of the bug were:
  NSE: Received only 0 of 1 expected responses.
  Decreasing max pipelined requests to 0.
  NSOCK (0.1870s) Write request for 0 bytes…
  nmap: nsock_core.c:516: handle_write_result: Assertion `bytesleft > 0′ failed.
  The error was reported by Brandon Enright and pyllyukko.
• [NSE] Restored the ability of http.head to return a body if the server returns one. This was lost in the http.lua overhaul from 5.20. [David]
• [NSE] Fixed the use of our strict.lua library on distributions that install their own strict.lua. The error message was
  nse_main.lua:97: attempt to call a boolean value
  It was reported by Onur K. [Patrick]
• Fixed handing of nameserver entries in /etc/resolv.conf so it could handle entries containing more than 16 bytes, which can occur with IPv6 addresses. Gunnar Lindberg reported the problem and contributed an initial patch, then Brandon and Kris refined and implemented it.
• [NSE] Corrected a behavior change in http.request that was accidentally made in 5.20: it could return nil instead of a table indicating failure. [David]
• [NSE] Fixed the use of an undefined variable in smb-enum-sessions, reported by Brandon. [Ron]
• Fixed a compiler error when –without-liblua is used. [Brandon]
• [NSE] Fixed an error with running http-enum.nse along with the –datadir option. The script would report the error http-enum.nse:198: bad argument #1 to ‘lines’ (nselib/data/http-fingerprints: No such file or directory) The error was reported by Ron Meldau and Brandon. [Kris]
• Added a function that was missing from http-favicon.nse. Its absence would cause the error
  http-favicon.nse:141: variable ‘dirname’ is not declared
  when a web page specified an relative icon URL through the link element. This bug was reported by Ron Meldau. [David]
• Fixed a bug with the decoding of NMAP OID component values ​​greater than 127. [Patrik Karlsson, David]

Enjoy the new release!
-Fyodor