mailing list archives
Re: Nmap Bug
From: David Fifield <david () bamsoftware com>
Date: Fri, 26 Jul 2013 18:36:20 -0700
On Fri, Jun 28, 2013 at 07:07:26AM -0700, avila () ltceng com wrote:
I discovered a nasty bug in nmap while attempting to scan a large
network. The reverse DNS was being done entirely through the
/etc/hosts file on a Linux RH 6.2 system. We required the exact
hostname to be returned from nmap via reserve lookup.
The problem was troubleshoot and fixed on nmap version 6.25. To
correct the problem the source file "nmap_dns.cc" was modified:
#define HASH_TABLE_SIZE 256
was changed to
#define HASH_TABLE_SIZE 4096
I may go back and change the routine further to make the hash
dynamic but this appears to not fine for our use of nmap.
Thanks for sending this report. Can you tell us what version of Nmap you
were using? I suspect this might have been a bug that was fixed in r7515
That bug caused most IP addresses to end up in the same hash bucket in
little-endian architectures. That wouldn't have prevented entries from
being found in the hash table, though; it only made it slower.
I don't see how your change would have fixed the problem; maybe I don't
understand you correctly?
Sent through the dev mailing list
Archived at http://seclists.org/nmap-dev/
- Re: Nmap Bug David Fifield (Jul 27)