3.1.3 Ensure DCCP is disabled - blacklist

Information

The Datagram Congestion Control Protocol (DCCP) is a transport layer protocol that supports streaming media and telephony. DCCP provides a way to gain access to congestion control, without having to do it at the application layer, but does not provide in-sequence delivery.

Rationale:

If the protocol is not required, it is recommended that the drivers not be installed to reduce the potential attack surface.

Solution

Run the following script to disable dccp:

#!/usr/bin/env bash

{
l_mname='dccp' # set module name
# Check if the module exists on the system
if [ -z '$(modprobe -n -v '$l_mname' 2>&1 | grep -Pi -- 'h*modprobe:h+FATAL:h+Moduleh+$l_mnameh+noth+foundh+inh+directory')' ]; then
# Remediate loadable
l_loadable='$(modprobe -n -v '$l_mname')'
[ '$(wc -l <<< '$l_loadable')' -gt '1' ] && l_loadable='$(grep -P -- '(^h*install|b$l_mname)b' <<< '$l_loadable')'
if ! grep -Pq -- '^h*install /bin/(true|false)' <<< '$l_loadable'; then
echo -e ' - setting module: '$l_mname' to be not loadable'
echo -e 'install $l_mname /bin/false' >> /etc/modprobe.d/'$l_mname'.conf
fi
# Remediate loaded
if lsmod | grep '$l_mname' > /dev/null 2>&1; then
echo -e ' - unloading module '$l_mname''
modprobe -r '$l_mname'
fi
# Remediate deny list
if ! modprobe --showconfig | grep -Pq -- '^h*blacklisth+$(tr '-' '_' <<< '$l_mname')b'; then
echo -e ' - deny listing '$l_mname''
echo -e 'blacklist $l_mname' >> /etc/modprobe.d/'$l_mname'.conf
fi
else
echo -e ' - Nothing to remediate
- Module '$l_mname' doesn't exist on the system'
fi
}

See Also

https://workbench.cisecurity.org/files/4115

Item Details

Category: CONFIGURATION MANAGEMENT

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

Plugin: Unix

Control ID: 9008ee121d6b013ed78a819fb83913dd801dc9e4fb5124a349834f10271f736c