FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

postgresql-server -- Role pg_cancel_backend can signal certain superuser processes

Affected packages
postgresql-server < 16.1
postgresql-server < 15.5
postgresql-server < 14.10
postgresql-server < 13.13
postgresql-server < 12.17
postgresql-server < 11.22


VuXML ID bbb18fcb-7f0d-11ee-94b4-6cc21735f730
Discovery 2023-11-09
Entry 2023-11-09

PostgreSQL Project reports:

Documentation says the pg_cancel_backend role cannot signal "a backend owned by a superuser". On the contrary, it can signal background workers, including the logical replication launcher. It can signal autovacuum workers and the autovacuum launcher. Signaling autovacuum workers and those two launchers provides no meaningful exploit, so exploiting this vulnerability requires a non-core extension with a less-resilient background worker. For example, a non-core background worker that does not auto-restart would experience a denial of service with respect to that particular background worker.


CVE Name CVE-2023-5870