Finding ID | Version | Rule ID | IA Controls | Severity |
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V-22416 | GEN003609 | SV-45726r1_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 modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. |
STIG | Date |
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SUSE Linux Enterprise Server v11 for System z | 2016-12-20 |
Check Text ( C-43093r1_chk ) |
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Verify the system does not accept IPv4 ICMP redirect messages. # grep [01] /proc/sys/net/ipv4/conf/*/accept_redirects|egrep "default|all" If all of the resulting lines do not end with "0", this is a finding. |
Fix Text (F-39124r1_fix) |
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Configure the system to not accept IPv4 ICMP redirect messages. Edit /etc/sysctl.conf and add a setting for "net.ipv4.conf.all.accept_redirects=0" and "net.ipv4.conf.default.accept_redirects=0". # sysctl -p |