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SOCLE-CLD-PKG-033// Packagesmediuminventory state

Remove the GDM Package Group

Removes the GNOME Display Manager (gdm) so headless and server systems carry no graphical login stack.

Checked against what is installed or registered, packages present/absent, account databases.

A pass proves✓ running now✓ on disk✓ survives rebootthe qualified verdict →
Debian 12CIS 1.1.0Debian 13CIS 1.0.0FedoraRHEL 10 / Rocky 10 / AlmaLinux 10RHEL 8 / Rocky 8 / AlmaLinux 8CIS 4.0.0RHEL 9 / Rocky 9 / AlmaLinux 9CIS 2.0.0Ubuntu 22.04CIS 3.0.0Ubuntu 24.04CIS 1.0.0Ubuntu 26.04
One check, maps to 2 standards

A mapping is a cross-reference to where each standard places this requirement, anchored and cross-validated, not a claim of equivalence. A passing check is evidence toward these references, how to read it.

Why this rule matters

The GNOME Display Manager (gdm) pulls in a full graphical login stack that is unnecessary on servers, virtualization hypervisors and headless hosts. Each extra service is additional code that can contain vulnerabilities and additional attack surface. Removing the graphical environment from systems that do not need it enforces the principle of least functionality required by CIS and NIST CM-7.

What Pavois checks

Pavois queries the package database with package('gdm') to report the effective install state. This is more reliable than checking the default systemd target or an X session file: the display manager package can remain installed even when the system boots to multi-user.target, and only a package query reveals that residual surface.

describe package('gdm3') do
  it { should_not be_installed }
end

How to verify it is applied

On RHEL-family run rpm -q gdm; on Debian/Ubuntu run dpkg -s gdm3 (the package is named gdm3 there). The rule passes when the result is package ... is not installed.

Inspect & investigate

Confirm removal with rpm -q gdm / dpkg -s gdm3. The display manager's own activity (when present) is in journalctl -u gdm / journalctl -u gdm3; removal is logged in /var/log/dnf.log or /var/log/dpkg.log.

Remediation

Pavois's harden plan removes the gdm package (resource package, action remove) when you run pavois harden apply. Removing the display manager stops the graphical login, so the host will boot to a text console afterwards.

Pavois applies this with its own harden engine, the plan below, not a shell script:

actionremove
namegdm3
resourcepackage
pavois harden plan local

where the target is local, a user@host SSH alias, or a container , Docs

Impact & precautions

Do not apply on workstations or any host where a graphical desktop is required, removing gdm disables the graphical login and may drag in dependent GNOME packages. Precaution: only run this on servers/hypervisors that are administered over SSH or a text console; ensure you have working remote/console access before removing, since the local graphical session will no longer be available.

Standards mapping

StandardReferenceTypeVersionConfidence
CIS1.7.1, 1.8.1, 2.1.21directper OS, see the benchmark tablehigh
NISTCM-6(a), CM-7(a), CM-7(b)supporting800-53 Rev 5 · 800-171 Rev 2 (pinned)medium

Each reference is a cross-reference anchored in the upstream benchmark and cross-validated against the SCAP Security Guide and ansible-lockdown, not a claim of equivalence. Direct = a prescriptive, line-level requirement; supporting = an abstract control family (NIST) the check provides evidence toward. How to read a mapping.

Sources & references