[krbdev.mit.edu #6967] Kerberos weakness

[Shelby@krbdev.mit.edu]

Thanks.  Ideally that would work similar to mac by using the keyring.  I just need to read the documentation on removing the /tmp/krb5cc file as it exploits the entire network for the duration of the ticket life.



-----Original Message-----
From: Russ Allbery via RT [mailto:rt-comment at krbdev.mit.edu] 
Sent: Friday, September 30, 2011 12:43 PM
To: Shelby, James
Subject: Re: [krbdev.mit.edu #6967] Kerberos weakness

Shelby at krbdev.mit.edu, James " via RT" <rt-comment at krbdev.mit.edu> writes:

> Is there a reason that the current Kerberos allows a KRB5CCNAME file to
> be created instead of being in memory?  This appears to be a weak link
> in the security of the Kerberos protocol as the file can be moved from
> system and allow passwordless access to resources the account has access
> to.

It's nice to be able to share ticket caches between processes (where nice
really means "mandatory" for most Kerberos use cases).

On Linux, you can use the KEYRING:* ticket cache type, which uses the
kernel keyring and may have more of the behavior that you're looking for,
although you still have the problem that anyone with access to read the
ticket cache can still copy it.

Memory ticket caches are of course supported, but aren't widely used
because of all the limitations involving passing tickets to subprocesses.

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>