CVE-2018-1053

In postgresql 9.3.x before 9.3.21, 9.4.x before 9.4.16, 9.5.x before
9.5.11, 9.6.x before 9.6.7 and 10.x before 10.2, pg_upgrade creates file in
current working directory containing the output of pg_dumpall -g under
umask which was in effect when the user invoked pg_upgrade, and not under
0077 which is normally used for other temporary files. This can allow an
authenticated attacker to read or modify the one file, which may contain
encrypted or unencrypted database passwords. The attack is infeasible if a
directory mode blocks the attacker searching the current working directory
or if the prevailing umask blocks the attacker opening the file.

Bugs

• <https://bugs.launchpad.net/ubuntu/+source/postgresql-9.5/+bug/1747676&gt;