Finding ID | Version | Rule ID | IA Controls | Severity |
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V-72293 | RHEL-07-040660 | SV-86917r2_rule | Medium |
Description |
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ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table, possibly revealing portions of the network topology. |
STIG | Date |
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Red Hat Enterprise Linux 7 Security Technical Implementation Guide | 2017-07-08 |
Check Text ( C-72527r2_chk ) |
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Verify the system does not send IPv4 ICMP redirect messages. Check the value of the "all send_redirects" variables with the following command: # grep 'net.ipv4.conf.all.send_redirects' /etc/sysctl.conf net.ipv4.conf.all.send_redirects=0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. |
Fix Text (F-78647r2_fix) |
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Configure the system to not allow interfaces to perform IPv4 ICMP redirects. Set the system to the required kernel parameter by adding the following line to "/etc/sysctl.conf" (or modify the line to have the required value): net.ipv4.conf.all.send_redirects=0 |