Title

Network interfaces must not be in promiscuous mode. (Cat II impact)

Discussion

Network interfaces in promiscuous mode allow for the capture of all network traffic visible to the system. If unauthorized individuals can access these applications, it may allow then to collect information such as logon IDs, passwords, and key exchanges between systems. If the system is being used to perform a network troubleshooting function, the use of these tools must be documented with the Information System Security Officer (ISSO) and restricted to only authorized personnel.

Check Content

Verify network interfaces are not in promiscuous mode unless approved by the Information System Security Officer (ISSO) and documented. Check for the status with the following command: # ip link | grep -i promisc If network interfaces are found on the system in promiscuous mode and their use has not been approved by the ISSO and documented, this is a finding.

Fix Text

Configure network interfaces to turn off promiscuous mode unless approved by the Information System Security Officer (ISSO) and documented. Set the promiscuous mode of an interface to "off" with the following command: # sudo ip link set dev <devicename> promisc off

Additional Identifiers

Rule ID: SV-215154r610931_rule

Vulnerability ID: V-215154

Group Title: SRG-OS-000480-GPOS-00227

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.