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Disable XDMCP in GDM

An XCCDF Rule

Description

XDMCP is an unencrypted protocol, and therefore, presents a security risk, see e.g. XDMCP Gnome docs. To disable XDMCP support in Gnome, set Enable to false under the [xdmcp] configuration section in /etc/gdm/custom.conf. For example:

[xdmcp]
Enable=false

Rationale

XDMCP provides unencrypted remote access through the Gnome Display Manager (GDM) which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using XDMCP, the privileged user password could be compromised due to typed XEvents and keystrokes will traversing over the network in clear text.

ID
xccdf_org.ssgproject.content_rule_gnome_gdm_disable_xdmcp
Severity
High
Updated