[nsp-sec] Cisco Security Advisory: SNMP Version 3Authentication Vulnerabilities

[Smith, Donald]

Since this is a one byte HMAC hash attack it seems you would have to have an HMAC configured to get a match.
Thus I believe you have to have configured snmpv3 in order to be vulnerable. 
 
donald.smith at qwest.com giac

________________________________

From: nsp-security-bounces at puck.nether.net on behalf of Eli Dart
Sent: Tue 6/10/2008 5:26 PM
To: nsp-security at puck.nether.net
Subject: Re: [nsp-sec] Cisco Security Advisory: SNMP Version 3Authentication Vulnerabilities



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[snip]

> Multiple Cisco products contain either of two authentication
> vulnerabilities in the Simple Network Management Protocol version 3
> (SNMPv3) feature. These vulnerabilities can be exploited when
> processing a malformed SNMPv3 message. These vulnerabilities could
> allow the disclosure of network information or may enable an attacker
> to perform configuration changes to vulnerable devices. The SNMP
> server is an optional service that is disabled by default in Cisco
> products. Only SNMPv3 is impacted by these vulnerabilities.
            ^^^^^^^^^^^^^^^^^^^^^^^^

Does this mean that only SNMPv3 packets can exploit the vulnerability,
or that the router must be configured for SNMPv3 in order to be vulnerable?

For example, changing to a different version of SNMP is not listed in
the workarounds section.


                --eli

- --
Eli Dart                                         Office: (510) 486-5629
ESnet Network Engineering Group                  Fax:    (510) 486-6712
Lawrence Berkeley National Laboratory
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