Finding ID | Version | Rule ID | IA Controls | Severity |
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V-22550 | GEN007860 | SV-37616r2_rule | ECSC-1 | 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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Red Hat Enterprise Linux 5 Security Technical Implementation Guide | 2014-04-02 |
Check Text ( C-36813r3_chk ) |
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Verify the system is configured to ignore IPv6 ICMP redirect messages. # cat /proc/sys/net/ipv6/conf/all/accept_redirects If the /proc/sys/net/ipv6/conf/all/accept_redirects entry does not exist because of compliance with GEN007720, this is not a finding. If the returned value is not "0", this is a finding. |
Fix Text (F-31651r1_fix) |
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Configure the system to ignore IPv6 ICMP redirect messages. Edit "/etc/sysctl.conf" and add a settings for "net.ipv6.conf.default.accept_redirects=0" and "net.ipv6.conf.all.accept_redirects=0". Restart the system for the setting to take effect. |