Re: In regards to the insecurity of AOL Instant Messenger

[John Scimone <sert () snosoft com>]

On Tuesday 06 August 2002 12:51 pm, jbarbo1 wrote:
> > Now my question, is how secure are normal "ims" on AIM. How difficult =
> > would it be to listen to anothers msgs and if at all possible, how could =
> > this be fixed.=20
>
> Sniffing the line that the messages are transferred on would reveal the
> contents. They are not encrypted. Maybe if encryption was used, it would
> prevent eavesdropping, at least, some of it.
>
> What about a man in the middle attack, anyone know of that being done
> sucessfully? Posing as the main AIM server, then redirecting the contents
> of the messages to the real server. Even on a side note, has anything ever
> been done like an Open AIM Server. I know people have created open clients,
> but what about an open server for it?

Does the AIM protocol have any kind of authentication to defeat MiM attacks 
whereby an attacker couldn't drop himself in the middle and log all outgoing 
conversations and change the actual conversation if he wanted?  I don't know 
much about the protocol and I'm pretty sure it's closed source, but has 
enough work been done by researchers into the protocol to determine if this 
is possible.  It seems to be it would be trivial for AOL's server to have a 
random id generated upon every successful login attempt by a user that would 
need to be included with every message and action on the client side in order 
for it to register.  This would at least prevent an attack by hopping into 
the middle of a conversation and would require a more extensive attack by 
being in the middle for the initial login.