Great Circle Associates Firewalls
(September 1997)
 

Indexed By Date: [Previous] [Next] Indexed By Thread: [Previous] [Next]

Subject: Re: SNMP security holes?!
From: greg @ webnology . com
Date: Tue, 2 Sep 1997 20:43:41 +0000
To: Juan Francisco Lopez <flopez @ wizard . infovia . com . gt>, firewalls @ GreatCircle . COM
Comments: Authenticated sender is <greg @ mail . webnology . com>

> Hello everyone!
> 
> Does any of you know of any security hole that are related to the use
> of SNMP? Can someone break into a network by using any SNMP based tool?
> What are the recommended filters to put into the routers and/or servers
> in order to avoid any break-through? (using Cisco routers, Linux and
> NT servers) ...
>           TIA for any feedback...

Yes,
SNMPv1 passes community names in plain text, and anyone with a packet 
sniffer along the route that the packet takes will be able to capture 
the read-write community name.  If this is captured, they have the 
ability to modify or destroy router configs etc...  Depending on the 
level of control incorporated into each hardware vendors private MIB 
structure, (and whether those devices are manageable on your private 
network) they can do a heck of a lot of damage to other devices as 
well.  Access lists on the routers should be more than sufficient to 
prevent outside management attempts (even if the community names had 
been captured), however firewalling to the application layer to 
prevent outside management would significantly bolster your security 
level.  

Personally I've always maintained that any level of security that first 
'accepts' a lack of physical security is worthless.  So, I guess what 
I'm saying is, if you can't keep a guy with a sniffer outta yer network, 
then keeping everyone else out is an exercise in futility.




Respectfully,

Greg Barnes
Webnology LLC

 ________________________________________________
|\===============W=E=B=N=O=L=O=G=Y===============\
     greg @
 webnology .
 com    Phone  (830)768-2292
     noc @
 webnology .
 com     FAX    (830)774-1518
|/===============W=E=B=N=O=L=O=G=Y===============/

'If you're a horse and someone gets on you and
 falls off, then gets right back on you...I think
 you should buck him off right away'
      -- Deep Thoughts, By Jack Handey


Indexed By Date Previous: Re: Real Audio
From: Paul Ferguson <ferguson @ cisco . com>
Next: IPMasquerading question (second post)
From: "Hanno Pet" <HPet @ svb . nl>
Indexed By Thread Previous: FW: SNMP security holes?!
From: "Stackpole, Bill" <BSTACKPO @ sla . com>
Next: Re: How many CPU's in your Firewall?
From: Mike Jones <mike . jones @ unifiedtech . com>

Google
 
Search Internet Search www.greatcircle.com