1.8.10 Ensure XDCMP is not enabled

Information

X Display Manager Control Protocol (XDMCP) is designed to provide authenticated access to display management services for remote displays

Rationale:

XDMCP is inherently insecure.

XDMCP is not a ciphered protocol. This may allow an attacker to capture keystrokes entered by a user

XDMCP is vulnerable to man-in-the-middle attacks. This may allow an attacker to steal the credentials of legitimate users by impersonating the XDMCP server.

Solution

Edit the file /etc/gdm3/custom.conf and remove the line:

Enable=true

Default Value:

false (This is denoted by no Enabled= entry in the file /etc/gdm3/custom.conf in the [xdmcp] section

See Also

https://workbench.cisecurity.org/benchmarks/13007

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, 800-53|CM-7, CSCv7|9.2

Plugin: Unix

Control ID: fc8f21811be6301d044dd950a51ca301444a0e74a22b54b134a5a191569051a1