On 4/11/22 16:10, Rob Sargent wrote:
I'm using postgres 14 in a database recently brought over from postgres
10. (I did not do the bringing over.)
In my set-up, I partition datasets by schema, create a role per schema
and part of that is this explicit permission granting (from superuser):
p\g
grant all on all tables in schema base, bulk, sgstemplate to
sgstemplate\p\g
--where sgstemplate is sedded to the real deal by the installer
there is no explicit 'public' in that set-up and here-to-fore the new
grantee has been able to see into public stuff just fine, in particular
to public functions which rely on getting grantee's version of tables
(replicated in sister schema).
I've just bumped into this.
barnard=> select public.genome_threshold_mono('a'::text,'b'::text);
ERROR: permission denied for schema public
LINE 1: select public.genome_threshold_mono('a'::text,'b'::text);
I know I haven't intentionally removed 'public' from grantee's purview
and short of the code block above not actually getting run, any guesses
as to how access to 'public' got removed from grantee?
I'm going to say someone read this:
https://wiki.postgresql.org/wiki/A_Guide_to_CVE-2018-1058:_Protect_Your_Search_Path
And did something along the line of this:
"
Next Steps: How Can I Protect My Databases?
Do not allow users to create new objects in the public schema
As a superuser, run the following command in all of your databases:
REVOKE CREATE ON SCHEMA public FROM PUBLIC;
Running REVOKE CREATE ON SCHEMA public FROM PUBLIC; prevents all
non-superusers from creating objects in the public schema. This setting
will protect a PostgreSQL database from the problem described in
CVE-2018-1058.
Once this command is run, certain operations could fail within your
database. For example, a non-superuser will not be able to create tables
or functions anymore with the public schema, which may affect how a user
manages application schema migrations.
Note that the REVOKE command is more powerful than running DROP SCHEMA
public; as pg_dump does not preserve the public schema removal.
After running this command, you should strongly consider auditing your
public schema to see if any users have created functions that have names
similar to ones in the pg_catalog. From the command-line tool (e.g.
psql), you can see a list of functions available in the public schema by
running:
\df public.*
To see a full list of functions defined In the pg_catalog schema, please
run:
\df pg_catalog.*
"
Probably should take a look at what permissions the functions in public
have?
I've run those grants specifically naming public and all is well. Do I
need to add that to the installer script?
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
