Finding ID | Version | Rule ID | IA Controls | Severity |
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V-253129 | TOSS-04-040880 | SV-253129r991589_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. There are notable differences between Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6). There is only a directive to disable sending of IPv4 redirected packets. Refer to RFC4294 for an explanation of "IPv6 Node Requirements", which resulted in this difference between IPv4 and IPv6. |
STIG | Date |
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Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide | 2024-05-30 |
Check Text ( C-56582r825057_chk ) |
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Verify TOSS does not IPv4 ICMP redirect messages. Note: If IPv4 is disabled on the system, this requirement is Not Applicable. Check the value of the "all send_redirects" variables with the following command: $ sudo sysctl net.ipv4.conf.all.send_redirects 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-56532r825058_fix) |
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Configure TOSS to not allow interfaces to perform IPv4 ICMP redirects with the following command: $ sudo sysctl -w net.ipv4.conf.all.send_redirects=0 If "0" is not the system's default value then add or update the following line in the appropriate file under "/etc/sysctl.d": net.ipv4.conf.all.send_redirects=0 |