Re: SNMP Reflected Denial Of Service - PoC

[Anestis Bechtsoudis <bechtsoudis.a () gmail com>]

Just tested on Windows 2003R2 & 2008R2 Server snmpd with same results
(no reflection). If you could name some devices/services that this
getBulk vector works will be extremely useful.



-A

On 9/3/12 1:03 AM, Full Disclosure wrote:
> Actually, if you test it against windows snmpd or a lot of Cable modems out there, the getbulk request causes a 1500 
> byte packet reply.
> You probably tested it against linux snmpd or cisco, which in that case , yes, it returns null. 
>
> 31.08.2012, 09:31, "Anestis Bechtsoudis" <bechtsoudis.a () gmail com>:
> > On 8/30/12 8:13 PM, Full Disclosure wrote:
> >
> > >  Hi list,
> > >
> > >  I am releasing this code due to the fact that my dev server got hacked and people have been using it in the wild 
> > > for bad things.
> > >
> > >  Network admins should patch their networks appropriately by rejecting snmp connections from unwanted IPs.
> >
> > The quoted code is actually nothing more than a regular threaded UDP
> > flood DoS tool, both SNMP spoofed requests and responses are equally 65
> > bytes (no reflection). Make a simple network capture for verification.
> >
> > The payload is a mis-used .1.3.6.1 getBulk SNMP request resulting in a
> > null value response.
> >
> > A sample perl script with the biggest reflection factor per transaction
> > achieved on Cisco devices is available here [1] (Amplification = 84
> > bytes request / 1480 bytes response).
> >
> > For more information about SNMP reflection DoS you may refer to this
> > link [2].
> >
> > The quoted code reminds me an old implementation on the same concept [3].
> >
> > [1] http://pastebin.com/M9cJs89h
> > [2] https://bechtsoudis.com/hacking/snmp-reflected-denial-of-service/
> > [3] http://packetstormsecurity.org/DoS/snmpdos.c
> >
> > -A
> >
> > --
> > #----------------------------------------------#
> > | Anestis Bechtsoudis                          |
> > |                                              |
> > | Network Operation Center,                    |
> > | Laboratory for Computing (LabCom),           |
> > | Dept. of Computer Engineering & Informatics, |
> > | University of Patras, Greece                 |
> > |----------------------------------------------|
> > | Public Key: http://bit.ly/Q2f5gW             |
> > | Website: https://bechtsoudis.com             |
> > #----------------------------------------------#

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