nbesort.rb -- An Easy Way to Sort Nessus Results by Finding
No self respecting security engineer will tell you that they rely on automated vulnerability scanners to do the bulk of their analysis. Juicy findings that demonstrate the severity of the threat they represent usually come from thorough manual analysis. As a security engineer, it is this manual analyis of software that I live for, and it is by far my favorite part of testing. However, this is not to say that vulnerability scanners do not play an important role: without Tenable's Nessus (our vulnerability scanner of choice), I would be overwhelmed with the sheer volume of low level findings that I'd have to deal with before being free to "dive deep" into the assessment. Things like outdated software versions and known configuration issues make a lot of sense to be tested by an automated scanner then subsequently validated and interpreted by a trained engineer.
The problem with this approach lies in the fact that there are a lot of findings that Nessus generates, including many that are not useful for my scope of assessment. I know I'm not alone in being less than thrilled with the Flash-based frontend for Nessus that has been standard for a few versions now, and exporting the report to HTML is really just as annoying to deal with. It is for these reasons that I wrote a small script which I am now very happy to release to you: nbesort.rb.
The data that I need from Nessus is complete list of the issues it's raised, with affected hosts and ports listed under each finding. In this way, it is easy for me to discard irrelevant findings and to pinpoint every host in scope when I see that an issue is valid and important (and hopefully exploitable). Although this seems like a simple request, the mostly-broken Nessus web frontend is incapable of providing this information in an easily accessible way. Don't get me wrong: Nessus is great software. I just don't like the new way that data is displayed through a Flash frontend.
I am happy to announce that approval to release nbesort.rb to the world was granted, and the (open source) script is available on GitHub at https://github.com/davidshaw/nbesort.rb/
Using nbesort.rb to sort Nessus results by finding is very simple. The first
step to using nbesort.rb is to login to the web portal and export your
report as an NBE. This is the standard Nessus output, and the name of the
script should help you remember to export .nbe instead of .nessus.
nbesort.rb is a
Ruby (command line) script, executed by running
ruby nbesort.rb <your_nbe
file>. The resulting text will output to stdout, so if you want to save to
a file you just have to add >outfile.txt to the end.
I hope that nbesort.rb saves you a few minutes the next time you have to parse through a big Nessus output. Remember: every minute you save on the low-hanging fruit is another minute you get to spend banging away on the critical issues you're so close to cracking. Happy scanning!