CVE-2023-26604

Published: 3 March 2023

systemd before 247 does not adequately block local privilege escalation for some Sudo configurations, e.g., plausible sudoers files in which the "systemctl status" command may be executed. Specifically, systemd does not set LESSSECURE to 1, and thus other programs may be launched from the less program. This presents a substantial security risk when running systemctl from Sudo, because less executes as root when the terminal size is too small to show the complete systemctl output.

Notes

on https://github.com/systemd/systemd/issues/5666
upstream claims this is not a vulnerability.
upstream feature SYSTEMD_PAGERSECURE implemented
in systemd version 247.

This is only an issue if an administrator configured systemctl
access using sudo instead of using policykit, which is an
unlikely scenario. Per Red Hat bug, systemctl commands that use
the pager can run unprivileged. Setting priority to "low".

Status

Severity score breakdown

References

• https://medium.com/@zenmoviefornotification/saidov-maxim-cve-2023-26604-c1232a526ba7
• https://github.com/systemd/systemd/blob/main/NEWS#L4335-L4340
• https://blog.compass-security.com/2012/10/dangerous-sudoers-entries-part-2-insecure-functionality/
• https://www.cve.org/CVERecord?id=CVE-2023-26604
• NVD
• Launchpad
• Debian

Bugs

• https://github.com/systemd/systemd/issues/5666
• https://bugzilla.redhat.com/show_bug.cgi?id=2175611