CCE-95030-3Platform: cpe:/o:debian:debian_linux:11.x, cpe:/o:ubuntu:ubuntu_linux:20.04, cpe:/o:ubuntu:ubuntu_linux:22.04, cpe:/o:ubuntu:ubuntu_linux:23.04 | Date: (C)2020-10-15 (M)2023-09-01 |
This setting prevents the system from accepting ICMP redirects. ICMP redirects tell the system about alternate routes for sending traffic.
Rationale:
It is recommended that systems not accept ICMP redirects as they could be tricked into routing traffic to compromised machines. Setting hard routes within the system (usually a single default route to a trusted router) protects the system from bad routes.
Fix:
Set the net.ipv6.conf.all.accept_redirects and net.ipv6.conf.default.accept_redirects parameters to 0 in /etc/sysctl.conf and run sysctl -p command:
net.ipv6.conf.all.accept_redirects=0 net.ipv6.conf.default.accept_redirects=0
Modify active kernel parameters to match:
# /sbin/sysctl -w net.ipv6.conf.all.accept_redirects=0
# /sbin/sysctl -w net.ipv6.conf.default.accept_redirects=0
# /sbin/sysctl -w net.ipv6.route.flush=1
Parameter:
[no/yes]
Technical Mechanism:
Set the net.ipv6.conf.all.accept_redirects and net.ipv6.conf.default.accept_redirects parameters to 0 in /etc/sysctl.conf:
net.ipv6.conf.all.accept_redirects=0 net.ipv6.conf.default.accept_redirects=0
Modify active kernel parameters to match:
# /sbin/sysctl -w net.ipv6.conf.all.accept_redirects=0
# /sbin/sysctl -w net.ipv6.conf.default.accept_redirects=0
# /sbin/sysctl -w net.ipv6.route.flush=1
CCSS Severity: | CCSS Metrics: |
CCSS Score : 8.2 | Attack Vector: NETWORK |
Exploit Score: 3.9 | Attack Complexity: LOW |
Impact Score: 4.2 | Privileges Required: NONE |
Severity: HIGH | User Interaction: NONE |
Vector: AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H | Scope: UNCHANGED |
| Confidentiality: LOW |
| Integrity: NONE |
| Availability: HIGH |
| |
References: Resource Id | Reference |
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SCAP Repo OVAL Definition | oval:org.secpod.oval:def:65939 |
SCAP Repo OVAL Definition | oval:org.secpod.oval:def:85106 |
SCAP Repo OVAL Definition | oval:org.secpod.oval:def:87292 |
SCAP Repo OVAL Definition | oval:org.secpod.oval:def:92181 |