full-disclosure - Re: SNMP Reflected Denial Of Service

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Date: Fri, 31 Aug 2012 16:31:12 +0300
From: Anestis Bechtsoudis <bechtsoudis.a@...il.com>
To: Full Disclosure <full.disclosure@...dex.ru>
Cc: full-disclosure@...ts.grok.org.uk
Subject: Re: SNMP Reflected Denial Of Service - PoC

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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