| Dmitry Teselkin | af730f9 | 2018-08-16 11:29:55 +0300 | [diff] [blame] | 1 | # 3.1.2 Ensure packet redirect sending is disabled |
| 2 | # |
| 3 | # Description |
| 4 | # =========== |
| 5 | # ICMP Redirects are used to send routing information to other hosts. As a host |
| 6 | # itself does not act as a router (in a host only configuration), there is |
| 7 | # no need to send redirects. |
| 8 | # |
| 9 | # Rationale |
| 10 | # ========= |
| 11 | # An attacker could use a compromised host to send invalid ICMP redirects to |
| 12 | # other router devices in an attempt to corrupt routing and have users access |
| 13 | # a system set up by the attacker as opposed to a valid system. |
| 14 | # |
| 15 | # Audit |
| 16 | # ===== |
| 17 | # |
| 18 | # Run the following commands and verify output matches: |
| 19 | # |
| 20 | # # sysctl net.ipv4.conf.all.send_redirects |
| 21 | # net.ipv4.conf.all.send_redirects = 0 |
| 22 | # # sysctl net.ipv4.conf.default.send_redirects |
| 23 | # net.ipv4.conf.default.send_redirects = 0 |
| 24 | # |
| 25 | # Remediation |
| 26 | # =========== |
| 27 | # |
| 28 | # Set the following parameters in the /etc/sysctl.conf file: |
| 29 | # |
| 30 | # net.ipv4.conf.all.send_redirects = 0 |
| 31 | # net.ipv4.conf.default.send_redirects = 0 |
| 32 | # |
| 33 | # Run the following commands to set the active kernel parameters: |
| 34 | # |
| 35 | # # sysctl -w net.ipv4.conf.all.send_redirects=0 |
| 36 | # # sysctl -w net.ipv4.conf.default.send_red |
| 37 | |
| 38 | parameters: |
| 39 | linux: |
| 40 | system: |
| 41 | kernel: |
| 42 | sysctl: |
| 43 | net.ipv4.conf.all.send_redirects: 0 |
| 44 | net.ipv4.conf.default.send_redirects: 0 |