dblink_connect_u(3) PostgreSQL 9.4.15 Documentation dblink_connect_u(3)
NAME
dblink_connect_u - opens a persistent connection to a remote database,
insecurely
SYNOPSIS
dblink_connect_u(text connstr) returns text
dblink_connect_u(text connname, text connstr) returns text
DESCRIPTION
dblink_connect_u(3) is identical to dblink_connect(), except that it
will allow non-superusers to connect using any authentication method.
If the remote server selects an authentication method that does not
involve a password, then impersonation and subsequent escalation of
privileges can occur, because the session will appear to have
originated from the user as which the local PostgreSQL server runs.
Also, even if the remote server does demand a password, it is possible
for the password to be supplied from the server environment, such as a
~/.pgpass file belonging to the server's user. This opens not only a
risk of impersonation, but the possibility of exposing a password to an
untrustworthy remote server. Therefore, dblink_connect_u(3) is initially
installed with all privileges revoked from PUBLIC, making it
un-callable except by superusers. In some situations it may be
appropriate to grant EXECUTE permission for dblink_connect_u(3) to
specific users who are considered trustworthy, but this should be done
with care. It is also recommended that any ~/.pgpass file belonging to
the server's user not contain any records specifying a wildcard host
name.
For further details see dblink_connect().
PostgreSQL 9.4.15 2017 dblink_connect_u(3)
PostgreSQL 9.4.15 - Generated Wed Nov 29 18:15:19 CST 2017