Warning: Cisco RW community backdoor.

Tue Feb 27 04:06:42 UTC 2001

On 26 Feb 2001, Sean Donelan wrote:

> 
> It appears more than one vendor shared the same SNMP library (or
> SNMP programmer).  Folks have sent me evidence at least two other
> vendor's equipment has similar responses to the same SNMP community
> string ILMI.
> 
> However, there are other non-related SNMP issues.  Many SNMP
> implementations included the default community strings "public"
> and "private".  If the operator doesn't change them, the defaults
> may still work.  The other common SNMP implementation issue is if
> no community string is specified, the SNMP agent accepts any
> community string.
> 
> If you are checking your network, I'd suggest checking for all
> three possibilities.
> 
> 
> 

IMHO, if no communities are supplied, the SNMP daemon should not respond
at all.

While I agree that "public" and "private" are "wellknowns," in most
implementations, they at least show up in the code.  Cisco chose to hide
this one where it would not show up in the code.  That IMHO is a very bad
thing and does bad things to my confidence level in Cisco.

---
John Fraizer
EnterZone, Inc