RHEL 10 must enforce that network interfaces not be in promiscuous mode.

STIG ID: RHEL-10-800020  |  SRG: SRG-OS-000423-GPOS-00187 |  Severity: medium (CAT II)  |  CCI: CCI-002418 |  Vulnerability Id: V-281334

Vulnerability 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 them to collect information such as login 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 systems security officer (ISSO) and restricted to authorized personnel only.

Check

Verify RHEL 10 network interfaces are not in promiscuous mode with the following command:

$ sudo 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

Configure RHEL 10 network interfaces to turn off promiscuous mode unless approved by the ISSO and documented.

Set the promiscuous mode of an interface to "off" with the following command:

$ sudo ip link set dev <devicename> multicast off promisc off