Ensure default deny firewall policy - Chain OUTPUT

Information

With a default accept policy the firewall will accept any packet that is not configured to be denied. It is easier to white list acceptable usage than to black list unacceptable usage.

Solution

Run the following commands to implement a default DROP policy: # iptables -P INPUT DROP# iptables -P OUTPUT DROP# iptables -P FORWARD DROP

See Also

https://www.cisco.com/c/en/us/td/docs/security/firepower/623/configuration/guide/fpmc-config-guide-v623.html

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(12), CSCv6|9.2

Plugin: Unix

Control ID: eaa9ebbeb91b8b97e7ab5e560cc02004c47016ae3f72f32a57acc31f1a9f66d9