CVE-2021-3997

Related Vulnerabilities: CVE-2021-3997  

A flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time when too many nested directories are created in /tmp.

Description

A flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time when too many nested directories are created in /tmp.

Statement

Red Hat Enterprise Linux 8 has a default 1024 nofile limit, thus preventing `systemd-tmpfiles` from exhausting its stack and crashing. For this reason, this flaw has been rated as having a security impact of Low on Red Hat Enterprise Linux 8. For more information on default ulimit values, please see https://access.redhat.com/solutions/4482841. In OpenShift Container Platform (OCP) systemd package was shipped with OCP 4.7 as a one-off instance and all the later OCP releases (4.8, 4.9) are using systemd from RHEL 8. Hence, the systemd package shipped with OCP 4.7 will not be fixed and the fix will be consumed from RHEL 8.

Red Hat Enterprise Linux 8 has a default 1024 nofile limit, thus preventing systemd-tmpfiles from exhausting its stack and crashing. For this reason, this flaw has been rated as having a security impact of Low on Red Hat Enterprise Linux 8. For more information on default ulimit values, please see https://access.redhat.com/solutions/4482841.

In OpenShift Container Platform (OCP) systemd package was shipped with OCP 4.7 as a one-off instance and all the later OCP releases (4.8, 4.9) are using systemd from RHEL 8. Hence, the systemd package shipped with OCP 4.7 will not be fixed and the fix will be consumed from RHEL 8.

Additional Information

  • Bugzilla 2024639: CVE-2021-3997 systemd: Uncontrolled recursion in systemd-tmpfiles when removing files
  • CWE-674: Uncontrolled Recursion
  • FAQ: Frequently asked questions about CVE-2021-3997