The system must ignore ICMPv6 redirects by default.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
|---|---|---|---|---|
| RHEL-06-000099 | RHEL-06-000099 | RHEL-06-000099_rule | Medium |
| Description |
|---|
| An illicit ICMP redirect message could result in a man-in-the-middle attack. |
| STIG | Date |
|---|---|
| Red Hat Enterprise Linux 6 Security Technical Implementation Guide | 2013-02-05 |
Details
| Check Text ( C-RHEL-06-000099_chk ) |
|---|
| The status of the "net.ipv6.conf.default.accept_redirects" kernel parameter can be queried by running the following command: $ sysctl net.ipv6.conf.default.accept_redirects The output of the command should indicate a value of "0". If this value is not the default value, investigate how it could have been adjusted at runtime, and verify it is not set improperly in "/etc/sysctl.conf". If the correct value is not returned, this is a finding. |
| Fix Text (F-RHEL-06-000099_fix) |
|---|
| To set the runtime status of the "net.ipv6.conf.default.accept_redirects" kernel parameter, run the following command: # sysctl -w net.ipv6.conf.default.accept_redirects=0 If this is not the system's default value, add the following line to "/etc/sysctl.conf": net.ipv6.conf.default.accept_redirects = 0 |