Bugtraq: RE: EEYE: Microsoft ASN.1 Library Length Overflow Heap Corruption

[Bill Gallagher <Bill.Gallagher () augharue com>]

...
> In order to trigger the ASN.1 vulnerabilities an attacker has 
> to be able
> to get the target machine to invoke its BER decoding capabilities.  
I have read a good number of the posts here regarding this vulnerability and
have seen references to NTLM etc. as a pathway for attack. What about SNMP?,
it certainly uses ASN.1. Does MS's SNMP stack not use this DLL? - Must
check.

> I
> certainly don't know the details -- maybe someone here does? 
> -- but it's
> gotta be a little difficult to send a random network packet to get a
> desktop machine (that is, not a domain controller or an AD server or
> something) and get it to invoke MSASN1.
>
> I can imagine lots of attacks that require user intervention 
> to hit this
> one (like opening a hostile SSL-based web site) -- but can this be
> triggered without user intervention?
>
> thanks for more info -- tbird
Like the others, SNMP should never pass the perimeter defences, but we are
talking about the same internet that got hit by blaster, SQL-Slammer etc.
I'm still occasionally finding it difficult to get some admins to operate a
'default deny' stance on inbound ports, let alone outbound.