Re: Version scanning problem with "--version-intensity 0"

[doug () hcsw org]

Hi Makoto Shiotsuki,

On Mon, Jun 05, 2006 at 02:16:51PM +0900 or thereabouts, Makoto Shiotsuki wrote:
> Version scanning against udp ports with "--version-intensity 0" option
> causes nmap to crash.

Good find and thank you for reporting it!

I have confirmed this problem and I'm attaching a possible patch for 4.04BETA1.
The problem, as you mentioned, is that with really low version intensity levels
it is possible that no probes will be applied against UDP ports which isn't
being handled properly by the code. Since I added the version intensity system
I take full responsibility for this bug. :)

With the official nmap-service-probes file this bug only appears when scanning
with a version-intensity of 0 since the file contains a couple UDP probes of rarity 1.

I'm glad to hear somebody else is getting some use out of the version intensity
option! I use it frequently. Using an intensity of 0 is very useful if you only
want to try probes registered to the target port.

This problem doesn't occur with TCP because we always have at least one
probe to try: the NULL probe.

Thanks again for the report!

Doug

Attachment: nmap-4.04-super-low-intensity-bugfix.patch
Description:

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