OL 9 must not send Internet Control Message Protocol (ICMP) redirects.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-271875 | OL09-00-006032 | SV-271875r1092337_rule | CCI-000366 | medium |
| Description | ||||
| 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. The ability to send ICMP redirects is only appropriate for systems acting as routers. | ||||
| STIG | Date | |||
| Oracle Linux 9 Security Technical Implementation Guide | 2025-05-08 | |||
Related Frameworks
4 paths across 3 frameworks
Related Frameworks
NIST 800-531 mapping
CM-6
1.00
- DISA · 1 · disa_xccdf · related
- DISA · 2025-01-23 · disa_cci_list · equivalent
NIST 800-1712 mappings
3.4.1
1.00
- DISA · 1 · disa_xccdf · related
- DISA · 2025-01-23 · disa_cci_list · equivalent
- NIST · Rev 2 (Feb 2020, errata Jan 2021) · nist_800_171_app_d · equivalent
3.4.2
1.00
- DISA · 1 · disa_xccdf · related
- DISA · 2025-01-23 · disa_cci_list · equivalent
- NIST · Rev 2 (Feb 2020, errata Jan 2021) · nist_800_171_app_d · equivalent
CCI1 mapping
CCI-000366
1.00
- DISA · 1 · disa_xccdf · related
Details
Check Text (C-271875r1092337_chk)
Verify that OL 9 does not IPv4 ICMP redirect messages.
Check the value of the "all send_redirects" variables with the following command:
$ sysctl net.ipv4.conf.all.send_redirects
net.ipv4.conf.all.send_redirects = 0
If "net.ipv4.conf.all.send_redirects" is not set to "0" and is not documented with the information system security officer (ISSO) as an operational requirement or is missing, this is a finding.
Fix Text (F-75832r1092336_fix)
Configure OL 9 to not allow interfaces to perform IPv4 ICMP redirects.
Add or edit the following line in a single system configuration file in the "/etc/sysctl.d/" directory:
net.ipv4.conf.all.send_redirects = 0
Load settings from all system configuration files with the following command:
$ sudo sysctl --system