Message-ID: <416045c0e7deac5b9f25e5fc89beec2a702a0b4c.camel@cybertec.at>
Subject: Re: PG16.1 security breach?
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: "David G. Johnston" <david.g.johnston@gmail.com>
Cc: "Zwettler Markus (OIZ)" <Markus.Zwettler@zuerich.ch>, Joe Conway
	 <mail@joeconway.com>, "pgsql-general@lists.postgresql.org"
	 <pgsql-general@lists.postgresql.org>
Date: Mon, 10 Jun 2024 11:21:42 +0200
In-Reply-To: <CAKFQuwaMthLY0XFtv44EBwc=nAwJO0_onACZoG0bnj9jvPBA5Q@mail.gmail.com>
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Precedence: bulk

On Fri, 2024-06-07 at 07:42 -0700, David G. Johnston wrote:
> On Friday, June 7, 2024, Laurenz Albe <laurenz.albe@cybertec.at> wrote:
> > On Fri, 2024-06-07 at 13:54 +0000, Zwettler Markus (OIZ) wrote:
> > > > Another point to keep in mind is that by default, execute privilege=
 is granted to
> > > > PUBLIC for newly created functions (see Section 5.7 for more inform=
ation).
> > >=20
> > > Argh. No! What a bad habit!
> > >=20
> > > Might be good idea for an enhancement request to create a global para=
meter to disable this habit.
> >=20
> > I don't see the problem, since the default execution mode for functions=
 is
> > SECURITY INVOKER.
> >=20
> > But you can easily change that:
> >=20
> > =C2=A0 ALTER DEFAULT PRIVILEGES FOR ROLE function_creator REVOKE EXECUT=
E ON FUNCTION FROM PUBLIC;
>=20
> You named function_creator here when in this example the role creating th=
e new object is postgres.

Then use "postgres" rather than "function_creator".

An ALTER DEFAULT PRIVILEGES statement always only changes default privilege=
s for objects
created by a certain user.

> How is it that the default privilege granted to public doesn=E2=80=99t se=
em to care who the object creator
> is yet when revoking the grant one supposedly can only do so within the s=
cope of a single role?

I don't understand what you wrote.  ALTER DEFAULT PRIVILEGES also only appl=
ies to objects
created by a single role when you grant default privileges.

Yours,
Laurenz Albe