Fw: Re: Warning: Cisco RW community backdoor. (fwd)

[Simon Lyall <simon.lyall () ihug co nz>]

Further updates.. It's not TOO bad.

-- 
Simon Lyall.                |  Newsmaster  | Work: simon.lyall () ihug co nz
Senior Network/System Admin |              | Home: simon () darkmere gen nz
ihug, Auckland, NZ          | Asst Doorman | Web: http://www.darkmere.gen.nz

---------- Forwarded message ----------
Date: Mon, 26 Feb 2001 21:54:50 -0400
From: Joe Abley <jabley () automagic org>
To: nznog () list waikato ac nz
Subject: Fw: Re: Warning: Cisco RW community backdoor.

More details below.

-----Original Message-----
From: "James A. T. Rice" <jamesr () rd bbc co uk>
Date: Tue, 27 Feb 2001 01:46:37 +0000 (GMT)
Subject: Re: Warning: Cisco RW community backdoor.
To: <members () lonap net>, , , <ops () linx net>

Just a couple of things to note,

I've been asked what the backdoor is, if its the community "ILMI" or if
that was just an example, the answer is yes - "ILMI" is the backdoor
which gives read-write access to parts of the SNMP base.

Its looks like parts of my earlier email are somewhat misleading, the ILMI
community appears to only allow RW access to the system object and
possibly some more objects. Its not a 'standard' open RW community. hence
the damage caused by this backdoor is limited. There is still some write
access however, so the fix mentioned below is still highly recommended.

And of course - it allows people to read what IOS/model cisco you have,
which could be used to find exploitable bugs in that particular release.
Oh I wonder what the chances of having a router stolen due to discovery of
system.sysLocation is! :-)

Warm Regards
James

-- 
James A. T. Rice             | Email: jamesr () rd bbc co uk
Internet Operations Engineer | Phone: 01737 839 737
BBC Internet Services, Kingswood Warren, Tadworth, Surrey, UK.

On Tue, 27 Feb 2001, it was written:

> If your router responds to `snmpwalk router.isp.net.uk ILMI`, you
> probabally will want to do the following to disable it:
>    conf t
>    snmp-server community ILMI RO 99
>    access-list 99 deny any log
> (pick another spare access-list if 99 isn't available)
>
> If you dont, assuming your ios/hardware combination supports it,
> (most of the bigger routers do) anyone can do things like:
>           `snmpset router.isp.net.uk ILMI system.sysName.0 s \
>           "ALL YOUR ROUTER ARE BELONG TO US."`
> Thats a harmless example. You can do almost anything with RW snmp.
>
> Warm Regards
> James
>
> --
> James A. T. Rice             | Email: jamesr () rd bbc co uk
> Internet Operations Engineer | Phone: 01737 839 737
> BBC Internet Services, Kingswood Warren, Tadworth, Surrey, UK.







---------
To unsubscribe from nznog, send email to majordomo () list waikato ac nz
where the body of your message reads:
unsubscribe nznog