Re: executing Linux commands from the PostgreSQL server

Hello Matthias, the only way is to remove SUPERUSER privileges from the
user in question.

ALTER ROLE username WITH NOSUPERUSER;

If you do not have sufficient privileges, the database will display the
following error:

ERROR: must be superuser to COPY to or from an external program

Atte.
JRBM

El mar, 23 sept 2025 a las 6:55, Matthias Apitz (<guru(at)unixarea(dot)de>)
escribió:

>
> Hello,
>
> The other way I detected that the PostgreSQL user 'postgres' (or any
> other user who can use the COPY ... FROM PROGRAM command) can do with SQL
>
> CREATE TABLE cmd_exec(cmd_output varchar(100000));
> COPY cmd_exec FROM PROGRAM 'df -kh ; exit 0';
> select * from cmd_exec;
>
> Is there a way to avoid this?
>
> matthias
>
> --
> Matthias Apitz, ✉ guru(at)unixarea(dot)de, http://www.unixarea.de/
> +49-176-38902045
> Public GnuPG key: http://www.unixarea.de/key.pub
>
> Annalena Baerbock: "We are fighting a war against Russia ..." (25.1.2023)
>
> I, Matthias, I am not at war with Russia.
> Я не воюю с Россией.
> Ich bin nicht im Krieg mit Russland.
>
>
>