Reconnection can downgrade connection security settings

Many PostgreSQL-provided client applications have options that create additional database connections. Some of those applications reuse only the basic connection parameters (e.g. host, user, port), dropping others. If this drops a security-relevant parameter (e.g. channel_binding, sslmode, requirepeer, gssencmode), the attacker has an opportunity to complete a MITM attack or observe cleartext transmission.

Affected applications are clusterdb, pg_dump, pg_restore, psql, reindexdb, and vacuumdb. The vulnerability arises only if one invokes an affected client application with a connection string containing a security-relevant parameter.

This also fixes how the \connect command of psql reuses connection parameters, i.e. all non-overridden parameters from a previous connection string now re-used.

The PostgreSQL project thanks Peter Eisentraut for reporting this problem.

Version Information

Affected Version Fixed In Fix Published
13 13.1 Nov. 12, 2020
12 12.5 Nov. 12, 2020
11 11.10 Nov. 12, 2020
10 10.15 Nov. 12, 2020
9.6 9.6.20 Nov. 12, 2020
9.5 9.5.24 Nov. 12, 2020

For more information about PostgreSQL versioning, please visit the versioning page.

CVSS 3.0

Overall Score 8.1
Component client
Vector AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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