3.1.2 Ensure packet redirect sending is disabled 'net.ipv4.conf.all.send_redirects = 0 /etc/sysctl.conf /etc/sysctl.d/*'

Information

An attacker could use a compromised host to send invalid ICMP redirects to other router devices in an attempt to corrupt routing and have users access a system set up by the attacker as opposed to a valid system.

Solution

Set the following parameters in the /etc/sysctl.conf file - net.ipv4.conf.all.send_redirects = 0 net.ipv4.conf.default.send_redirects = 0 Run the following commands to set the active kernel parameters - # sysctl -w net.ipv4.conf.all.send_redirects=0
# sysctl -w net.ipv4.conf.default.send_redirects=0
# sysctl -w net.ipv4.route.flush=1

See Also

https://workbench.cisecurity.org/files/1863

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

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

Plugin: Unix

Control ID: a0558c607b67ec510434e681ba804ff70357b4744a84c10fb659318927e6479b