Re: prevent user change password?

Richard Hayward <richard@tortoise.demon.co.uk> writes:
> On Wed, 01 Jun 2005 11:39:22 -0400, tgl@sss.pgh.pa.us (Tom Lane)
> wrote:
>> Perhaps you should use something other than password authentication
>> for the guest account.

> I want anyone from anywhere to be able to connect to my_database (only
> my_database,  not others in the cluster) using the guest account. The
> system is to be live on the Internet.

> Putting:

> host  my_database  guest   0.0.0.0      0.0.0.0  trust

> ahead of other entries in pg_hba.conf seems to do the trick. Even if
> guest is given a password, or it gets changed, guest can connect
> without being asked for it.

> The guest account will only be allowed select permissions.

> Does this open me to being attacked? I assume guest could then query
> various system tables, but that other users passwords are either not
> visible or securely encrypted.

I'd be inclined to use a postmaster dedicated *only* to that purpose,
running under a Unix userid also dedicated to that purpose.  We do come
across security holes from time to time ...

            regards, tom lane