Role pg_signal_backend can signal certain superuser processes.
CVE: CVE-2023-5870
Component: postgresql
CWE: CWE-400
Severity: Low
CVSS v3: 2.7/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L
Release date: 2023-11-09T00:00:00+00:00

A flaw was found in PostgreSQL involving the pg_cancel_backend role that signals background workers, including the logical replication launcher, autovacuum workers, and the autovacuum launcher. Successful exploitation requires a non-core extension with a less-resilient background worker and would affect that specific background worker only. This issue may allow a remote high privileged user to launch a denial of service (DoS) attack.

Statement: Although the NVD assigns this issue a Moderate rating, Red Hat classifies it as Low severity because the practical impact is limited and requires multiple specific conditions. The vulnerability allows a privileged database role (pg_signal_backend) to send signals to certain background worker processes. However, PostgreSQL’s core background workers are designed to safely handle such signals and automatically recover without disrupting the database service.

For a denial-of-service condition to occur, the system must be running a non-core extension that introduces a custom background worker which is not designed to restart safely after receiving a signal. In other words, the issue does not affect standard PostgreSQL installations and only impacts specialized configurations using third-party extensions. Even in affected scenarios, the impact is limited to disruption of a specific auxiliary background task and does not result in complete database failure, data loss, or compromise of confidentiality or integrity.

Because exploitation requires a high-privileged user and affects only certain non-default configurations with limited operational impact, Red Hat considers the real-world risk to be Low.

Remediation:
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
If you are using an earlier version of RHACS 3.74, you are advised to upgrade to patch release 3.74.8.
If you are using an earlier version of RHACS 4.1, you are advised to upgrade to patch release 4.1.6.
Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

If the postgresql service is running, it will be automatically restarted after installing this update.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.